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Graduate teaching assistants (GTAs) in science, technology, engineering, and mathematics (STEM) have a large impact on undergraduate instruction but are often poorly prepared to teach. Teaching self-efficacy, an instructor’s belief in his or her ability to teach specific student populations a specific subject, is an important predictor of teaching skill and student achievement. A model of sources of teaching self-efficacy is developed from the GTA literature. This model indicates that teaching experience, departmental teaching climate (including peer and supervisor relationships), and GTA professional development (PD) can act as sources of teaching self-efficacy. The model is pilot tested with 128 GTAs from nine different STEM departments at a midsized research university. Structural equation modeling reveals that K–12 teaching experience, hours and perceived quality of GTA PD, and perception of the departmental facilitating environment are significant factors that explain 32% of the variance in the teaching self-efficacy of STEM GTAs. This model highlights the important contributions of the departmental environment and GTA PD in the development of teaching self-efficacy for STEM GTAs.Science, technology, engineering, and mathematics (STEM) graduate teaching assistants (GTAs) play a significant role in the learning environment of undergraduate students. They are heavily involved in the instruction of undergraduate students at master’s- and doctoral-granting universities (Nyquist et al., 1991 ; Johnson and McCarthy, 2000 ; Sundberg et al., 2005 ; Gardner and Jones, 2011 ). GTAs are commonly in charge of laboratory or recitation sections, in which they often have more contact and interaction with the students than the professor who is teaching the course (Abraham et al., 1997 ; Sundberg et al., 2005 ; Prieto and Scheel, 2008 ; Gardner and Jones, 2011 ).Despite the heavy reliance on GTAs for instruction and the large potential for them to influence student learning, there is evidence that many GTAs are completely unprepared or at best poorly prepared for their role as instructors (Abraham et al., 1997 ; Rushin et al., 1997 ; Shannon et al., 1998 ; Golde and Dore, 2001 ; Fagen and Wells, 2004 ; Luft et al., 2004 ; Sundberg et al., 2005 ; Prieto and Scheel, 2008 ). For example, in molecular biology, 71% of doctoral students are GTAs, but only 30% have had an opportunity to take a GTA professional development (PD) course that lasted at least one semester (Golde and Dore, 2001 ). GTAs often teach in a primarily directive manner and have intuitive notions about student learning, motivation, and abilities (Luft et al., 2004 ). For those who experience PD, university-wide PD is often too general (e.g., covering university policies and procedures, resources for students), and departmental PD does not address GTAs’ specific teaching needs; instead departmental PD repeats the university PD (Jones, 1993 ; Golde and Dore, 2001 ; Luft et al., 2004 ). Nor do graduate experiences prepare GTAs to become faculty and teach lecture courses (Golde and Dore, 2001 ).While there is ample evidence that many GTAs are poorly prepared, as well as studies of effective GTA PD programs (biology examples include Schussler et al., 2008 ; Miller et al., 2014 ; Wyse et al., 2014 ), the preparation of a graduate student as an instructor does not occur in a vacuum. GTAs are also integral members of their departments and are interacting with faculty and other GTAs in many different ways, including around teaching (Bomotti, 1994 ; Notarianni-Girard, 1999 ; Belnap, 2005 ; Calkins and Kelly, 2005 ). It is important to build good working relationships among the GTAs and between the GTAs and their supervisors (Gardner and Jones, 2011 ). However, there are few studies that examine the development of GTAs as integral members of their departments and determine how departmental teaching climate, GTA PD, and prior teaching experiences can impact GTAs.To guide our understanding of the development of GTAs as instructors, a theoretical framework is important. Social cognitive theory is a well-developed theoretical framework for describing behavior and can be applied specifically to teaching (Bandura, 1977 , 1986 , 1997 , 2001 ). A key concept in social cognitive theory is self-efficacy, which is a person’s belief in his or her ability to perform a specific task in a specific context (Bandura, 1997 ). High self-efficacy correlates with strong performance in a task such teaching (Bandura, 1997 ; Tschannen-Moran and Hoy, 2007 ). Teaching self-efficacy focuses on teachers’ perceptions of their ability to “organize and execute courses of action required to successfully accomplish a specific teaching task in a particular context” (Tschannen-Moran et al., 1998 , p. 233). High teaching self-efficacy has been shown to predict a variety of types of student achievement among K–12 teachers (Ashton and Webb, 1986 ; Anderson et al., 1988 ; Ross, 1992 ; Dellinger et al., 2008 ; Klassen et al., 2011 ). In GTAs, teaching self-efficacy has been shown to be related to persistence in academia (Elkins, 2005 ) and student achievement in mathematics (Johnson, 1998 ). High teaching self-efficacy is evidenced by classroom behaviors such as efficient classroom management, organization and planning, and enthusiasm (Guskey, 1984 ; Allinder, 1994 ; Dellinger et al., 2008 ). Instructors with high teaching self-efficacy work continually with students to help them in learning the material (Gibson and Dembo, 1984 ). These instructors are also willing to try a variety of teaching methods to improve their teaching (Stein and Wang, 1988 ; Allinder, 1994 ). Instructors with high teaching self-efficacy perform better as teachers, are persistent in difficult teaching tasks, and can positively affect their student’s achievement.These behaviors of successful instructors, which can contribute to student success, are important to foster in STEM GTAs. Understanding of what influences the development of teaching self-efficacy in STEM GTAs can be used to improve their teaching self-efficacy and ultimately their teaching. Therefore, it is important to understand what impacts teaching self-efficacy in STEM GTAs. Current research into factors that influence GTA teaching self-efficacy are generally limited to one or two factors in a study (Heppner, 1994 ; Prieto and Altmaier, 1994 ; Prieto and Meyers, 1999 ; Prieto et al., 2007 ; Liaw, 2004 ; Meyers et al., 2007 ). Studying these factors in isolation does not allow us to understand how they work together to influence GTA teaching self-efficacy. Additionally, most studies of GTA teaching self-efficacy are not conducted with STEM GTAs. STEM instructors teach in a different environment and with different responsibilities than instructors in the social sciences and liberal arts (Lindbloom-Ylanne et al., 2006 ). These differences could impact the development of teaching self-efficacy of STEM GTAs compared with social science and liberal arts GTAs. To further our understanding of the development of STEM GTA teaching self-efficacy, this paper aims to 1) describe a model of factors that could influence GTA teaching self-efficacy, and 2) pilot test the model using structural equation modeling (SEM) on data gathered from STEM GTAs. The model is developed from social cognitive theory and GTA teaching literature, with support from the K–12 teaching self-efficacy literature. This study is an essential first step in improving our understanding of the important factors impacting STEM GTA teaching self-efficacy, which can then be used to inform and support the preparation of effective STEM GTAs.  相似文献   

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A response to Maskiewicz and Lineback''s essay in the September 2013 issue of CBE-Life Sciences Education.Dear Editor:Maskiewicz and Lineback (2013) have written a provocative essay about how the term misconceptions is used in biology education and the learning sciences in general. Their historical perspective highlights the logic and utility of the constructivist theory of learning. They emphasize that students’ preliminary ideas are resources to be built upon, not errors to be eradicated. Furthermore, Maskiewicz and Lineback argue that the term misconception has been largely abandoned by educational researchers, because it is not consistent with constructivist theory. Instead, they conclude, members of the biology education community should speak of preconceptions, naïve conceptions, commonsense conceptions, or alternative conceptions.We respectfully disagree. Our objections encompass both the semantics of the term misconception and the more general issue of constructivist theory and practice. We now address each of these in turn. (For additional discussion, please see Leonard, Andrews, and Kalinowski , “Misconceptions Yesterday, Today, and Tomorrow,” CBE—Life Sciences Education [LSE], in press, 2014.)Is misconception suitable for use in scholarly discussions? The answer depends partly on the intended audience. We avoid using the term misconception with students, because it could be perceived as pejorative. However, connotations of disapproval are less of a concern for the primary audience of LSE and similar journals, that is, learning scientists, discipline-based education researchers, and classroom teachers.An additional consideration is whether misconception is still used in learning sciences outside biology education. Maskiewicz and Lineback claim that misconception is rarely used in journals such as Cognition and Instruction, Journal of the Learning Sciences, Journal of Research in Science Teaching, and Science Education, yet the term appears in about a quarter of the articles published by these journals in 2013 (National Research Council, 2012 ).

Table 1.

Use of the term misconception in selected education research journals in 2013
Journal (total articles published in 2013a)Articles using misconception (“nondisapproving” articles/total articles)Articles using other terms
LSE (59)23/24Alternative conception (4)
Commonsense conception (2)
Naïve conception (1)
Preconception (4)
Cognition and Instruction (16)3/3None
Journal of the Learning Sciences (17)4/4Commonsense science knowledge (1)
Naïve conception (1)
Prior conception (1)
Journal of Research in Science Teaching (49)11/13Commonsense idea (1)
Naïve conception (1)
Preconception (5)
Science Education (36)10/11Naïve conception (1)
Open in a separate windowaAs of November 25, 2013. Does not include very short editorials, commentaries, corrections, or prepublication online versions.A final consideration is whether any of the possible alternatives to misconception are preferable. We feel that the alternatives suggested by Maskiewicz and Lineback are problematic in their own ways. For example, naïve conception sounds more strongly pejorative to us than misconception. Naïve conception and preconception also imply that conceptual challenges occur only at the very beginning stages of learning, even though multiple rounds of conceptual revisions are sometimes necessary (e.g., see figure 1 of Andrews et al., 2012 ) as students move through learning progressions. Moreover, the terms preferred by Maskiewicz and Lineback are used infrequently (Smith et al. (1993) that they object to statements that misconceptions should be actively confronted, challenged, overcome, corrected, and/or replaced (Smith et al. (1993) argue on theoretical grounds that confrontation does not allow refinement of students’ pre-existing, imperfect ideas; instead, the students must simply choose among discrete prepackaged ideas. From Maskiewicz and Lineback''s perspective, the papers listed in Maskiewicz and Lineback (2013) as using outdated views of misconceptionsa
ArticleExample of constructivist languageExample of language suggesting confrontation
Andrews et al., 2011 “Constructivist theory argues that individuals construct new understanding based on what they already know and believe.… We can expect students to retain serious misconceptions if instruction is not specifically designed to elicit and address the prior knowledge students bring to class” (p. 400).Instructors were scored for “explaining to students why misconceptions were incorrect” and “making a substantial effort toward correcting misconceptions” (p. 399). “Misconceptions must be confronted before students can learn natural selection” (p. 399). “Instructors need to elicit misconceptions, create situations that challenge misconceptions.” (p. 403).
Baumler et al., 2012 “The last pair [of students]''s response invoked introns, an informative answer, in that it revealed a misconception grounded in a basic understanding of the Central Dogma” (p. 89; acknowledges students’ useful prior knowledge).No relevant text found
Cox-Paulson et al., 2012 No relevant text foundThis paper barely mentions misconceptions, but cites sources (Phillips et al., 2008 ; Robertson and Phillips, 2008 ) that refer to “exposing,” “uncovering,” and “correcting” misconceptions.
Crowther, 2012 “Prewritten songs may explain concepts in new ways that clash with students’ mental models and force revision of those models” (p. 28; emphasis added).“Songs can be particularly useful for countering … conceptual misunderstandings.… Prewritten songs may explain concepts in new ways that clash with students’ mental models and force revision of those models” (p. 28).
Kalinowski et al., 2010 “Several different instructional approaches for helping students to change misconceptions … agree that instructors must take students’ prior knowledge into account and help students integrate new knowledge with their existing knowledge” (p. 88).“One strategy for correcting misconceptions is to challenge them directly by ‘creating cognitive conflict,’ presenting students with new ideas that conflict with their pre-existing ideas about a phenomenon… In addition, study of multiple examples increases the chance of students identifying and overcoming persistent misconceptions” (p. 89).
Open in a separate windowaWhile these papers do not adhere to Smith et al.''s (1993) version of constructivism, they do adhere to the constructivist approach that advocates cognitive dissonance.Our own stance differs from that of Maskiewicz and Lineback, reflecting a lack of consensus within constructivist theory. We agree with those who argue that, not only are confrontations compatible with constructivist learning, they are a central part of it (e.g., Gilbert and Watts, 1983 ; Hammer, 1996 ). We note that Baviskar et al. (2009) list “creating cognitive dissonance” as one of the four main tenets of constructivist teaching. Their work is consistent with research showing that focusing students on conflicting ideas improves understanding more than approaches that do not highlight conflicts (e.g., Kowalski and Taylor, 2009 ; Gadgil et al., 2012 ). Similarly, the Discipline-Based Education Research report (National Research Council, 2012 , p. 70) advocates “bridging analogies,” a form of confrontation, to guide students toward more accurate ways of thinking. Therefore, we do not share Maskiewicz and Lineback''s concerns about the papers listed in Price, 2012 ). We embrace collegial disagreement.Maskiewicz and Lineback imply that labeling students’ ideas as misconceptions essentially classifies these ideas as either right or wrong, with no intermediate stages for constructivist refinement. In fact, a primary goal of creating concept inventories, which use the term misconception profusely (e.g., Morris et al., 2012 ; Prince et al., 2012 ), is to demonstrate that learning is a complex composite of scientifically valid and invalid ideas (e.g., Andrews et al., 2012 ). A researcher or instructor who uses the word misconceptions can agree wholeheartedly with Maskiewicz and Lineback''s point that misconceptions can be a good starting point from which to develop expertise.As we have seen, misconception is itself fraught with misconceptions. The term now embodies the evolution of our understanding of how people learn. We support the continued use of the term, agreeing with Maskiewicz and Lineback that authors should define it carefully. For example, in our own work, we define misconceptions as inaccurate ideas that can predate or emerge from instruction (e.g., Andrews et al., 2012 ). We encourage instructors to view misconceptions as opportunities for cognitive dissonance that students encounter as they progress in their learning.  相似文献   

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Course-based undergraduate research experiences (CUREs) may be a more inclusive entry point to scientific research than independent research experiences, and the implementation of CUREs at the introductory level may therefore be a way to improve the diversity of the scientific community.The U.S. scientific research community does not reflect America''s diversity. Hispanics, African Americans, and Native Americans made up 31% of the general population in 2010, but they represented only 18 and 7% of science, technology, engineering, and mathematics (STEM) bachelor''s and doctoral degrees, respectively, and 6% of STEM faculty members (National Science Foundation [NSF], 2013 ). Equity in the scientific research community is important for a variety of reasons; a diverse community of researchers can minimize the negative influence of bias in scientific reasoning, because people from different backgrounds approach a problem from different perspectives and can raise awareness regarding biases (Intemann, 2009 ). Additionally, by failing to be attentive to equity, we may exclude some of the best and brightest scientific minds and limit the pool of possible scientists (Intemann, 2009 ). Given this need for equity, how can our scientific research community become more inclusive?Current approaches to improving diversity in scientific research focus on graduating more STEM majors, but graduation with a STEM undergraduate degree alone is not ­sufficient for entry into graduate school. Undergraduate independent research experiences are becoming more or less a prerequisite for admission into graduate school and eventually a career in academia; a quick look at the recommendations for any of the top graduate programs in biology or science career–related websites state an expectation for ­undergraduate research and a perceived handicap if recommendation letters for graduate school do not include a ­discussion of the applicant''s research experience (Webb, 2007 ; Harvard ­University, 2013 ).Independent undergraduate research experiences have been shown to improve the retention of students in scientific research (National Research Council, 2003 ; Laursen et al., 2010 ; American Association for the Advancement of Science, 2011 ; Eagan et al., 2013 ). Participation in independent research experiences has been shown to increase interest in pursuing a PhD (Seymour et al., 2004 ; Russell et al., 2007 ) and seems to be particularly beneficial for students from historically underrepresented backgrounds (Villarejo et al., 2008 ; Jones et al., 2010 ; Espinosa, 2011 ; Hernandez et al., 2013 ). However, the limited number of undergraduate research opportunities available and the structure of how students are selected for these independent research lab positions exclude many students and can perpetuate inequities in the research community. In this essay, we highlight barriers faced by students interested in pursuing an undergraduate independent research experience and factors that impact how faculty members select students for these limited positions. We examine how bringing research experiences into the required course work for students could mitigate these issues and ultimately make research more inclusive.  相似文献   

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In science education, inquiry-based approaches to teaching and learning provide a framework for students to building critical-thinking and problem-solving skills. Teacher professional development has been an ongoing focus for promoting such educational reforms. However, despite a strong consensus regarding best practices for professional development, relatively little systematic research has documented classroom changes consequent to these experiences. This paper reports on the impact of sustained, multiyear professional development in a program that combined neuroscience content and knowledge of the neurobiology of learning with inquiry-based pedagogy on teachers’ inquiry-based practices. Classroom observations demonstrated the value of multiyear professional development in solidifying adoption of inquiry-based practices and cultivating progressive yearly growth in the cognitive environment of impacted classrooms.Current discussion about educational reform among business leaders, politicians, and educators revolves around the idea students need “21st century skills” to be successful today (Rotherham and Willingham, 2009 ). Proponents argue that to be prepared for college and to be competitive in the 21st-century workplace, students need to be able to identify issues, acquire and use new information, understand complex systems, use technologies, and apply critical and creative thinking skills (US Department of Labor, 1991 ; Bybee et al., 2007 ; Conley, 2007 ). Advocates of 21st-century skills favor student-centered methods—for example, problem-based learning and project-based learning. In science education, inquiry-based approaches to teaching and learning provide one framework for students to build these critical-thinking and problem-solving skills (American Association for the Advancement of Science [AAAS], 1993 ; National Research Council [NRC], 2000 ; Capps et al., 2012 ).Unfortunately, in spite of the central role of inquiry in the national and state science standards, inquiry-based instruction is rarely implemented in secondary classrooms (Weiss et al., 1994 ; Bybee, 1997 ; Hudson et al., 2002 ; Smith et al., 2002 ; Capps et al., 2012 ). Guiding a classroom through planning, executing, analyzing, and evaluating open-ended investigations requires teachers to have sufficient expertise, content knowledge, and self-confidence to be able to maneuver through multiple potential roadblocks. Researchers cite myriad reasons for the lack of widespread inquiry-based instruction in schools: traditional beliefs about teaching and learning (Roehrig and Luft, 2004 ; Saad and BouJaoude, 2012 ), lack of pedagogical skills (Shulman, 1986 ; Adams and Krockover, 1997 ; Crawford, 2007 ), lack of time (Loughran, 1994 ), inadequate knowledge of the practice of science (Duschl, 1987 ; DeBoer, 2004 ; Saad and BouJaoude, 2012 ), perceived time constraints due to high-stakes testing, and inadequate preparation in science (Krajcik et al., 2000 ). Yet teachers are necessarily at the center of reform, as they make instructional and pedagogical decisions within their own classrooms (Cuban, 1990 ). Given that effectiveness of teachers’ classroom practices is critical to the success of current science education reforms, teacher professional development has been an ongoing focus for promoting educational reform (Corcoran, 1995 ; Corcoran et al., 1998 ).A review of the education research literature yields an extensive knowledge base in “best practices” for professional development (Corcoran, 1995 ; NRC, 1996 ; Loucks-Horsley and Matsumoto, 1999 ; Loucks-Horsley et al., 2009 ; Haslam and Fabiano, 2001 ; Wei et al., 2010 ). However, in spite of a strong consensus on what constitutes best practices for professional development (Desimone, 2009 ; Wei et al., 2010 ), relatively little systematic research has been conducted to support this consensus (Garet et al., 2001 ). Similarly, when specifically considering the science education literature, several studies have been published on the impact of teacher professional development on inquiry-based practices (e.g., Supovitz and Turner, 2000 ; Banilower et al., 2007 ; Capps et al., 2012 ). Unfortunately, these studies usually rely on teacher self-report data; few studies have reported empirical evidence of what actually occurs in the classroom following a professional development experience.Thus, in this study, we set out to determine through observational empirical data whether documented effective professional development does indeed change classroom practices. In this paper, we describe an extensive professional development experience for middle school biology teachers designed to develop teachers’ neuroscience content knowledge and inquiry-based pedagogical practices. We investigate the impact of professional development delivered collaboratively by experts in science and pedagogy on promoting inquiry-based instruction and an investigative classroom culture. The study was guided by the following research questions:
  1. Were teachers able to increase their neuroscience content knowledge?
  2. Were teachers able to effectively implement student-centered reform or inquiry-based pedagogy?
  3. Would multiple years of professional development result in greater changes in teacher practices?
Current reforms in science education require fundamental changes in how students are taught science. For most teachers, this requires rethinking their own practices and developing new roles both for themselves as teachers and for their students (Darling-Hammond and McLaughlin, 1995 ). Many teachers learned to teach using a model of teaching and learning that focuses heavily on memorizing facts (Porter and Brophy, 1988 ; Cohen et al., 1993 ; Darling-Hammond and McLaughlin, 1995 ), and this traditional and didactic model of instruction still dominates instruction in U.S. classrooms. A recent national observation study found that only 14% of science lessons were of high quality, providing students an opportunity to learn important science concepts (Banilower et al., 2006 ). Shifting to an inquiry-based approach to teaching places more emphasis on conceptual understanding of subject matter, as well as an emphasis on the process of establishing and validating scientific concepts and claims (Anderson, 1989 ; Borko and Putnam, 1996 ). In effect, professional development must provide opportunities for teachers to reflect critically on their practices and to fashion new knowledge and beliefs about content, pedagogy, and learners (Darling-Hammond and McLaughlin, 1995 ; Wei et al., 2010 ). If teachers are uncomfortable with a subject or believe they cannot teach science, they may focus less time on it and impart negative feelings about the subject to their students. In this way, content knowledge influences teachers’ beliefs about teaching and personal self-efficacy (Gresham, 2008 ). Personal self-efficacy was first defined as “the conviction that one can successfully execute the behavior required to produce the outcomes” (Bandura, 1977 , p.193). Researchers have reported self-efficacy to be strongly correlated with teachers’ ability to implement reform-based practices (Mesquita and Drake, 1994 ; Marshall et al., 2009 ).Inquiry is “a multifaceted activity that involves making observations, posing questions, examining books and other sources of information, planning investigations, reviewing what is already known in light of evidence, using tools to gather, analyze and interpret data, proposing answers, explanations and predictions, and communicating the results” (NRC, 1996 , p. 23). Unfortunately, most preservice teachers rarely experience inquiry-based instruction in their undergraduate science courses. Instead, they listen to lectures on science and participate in laboratory exercises with guidelines for finding the expected answer (Gess-Newsome and Lederman, 1993 ; DeHaan, 2005 ). As such, teachers’ knowledge and beliefs about teaching and learning were developed over the many years of their own educations, through “apprenticeship of observation” (Lortie, 1975 ), in traditional lecture-based settings that they then replicate in their own classrooms. To support the implementation of inquiry in K–12 classrooms, teachers need firsthand experiences of inquiry, questioning, and experimentation within professional development programs (Gess-Newsome, 1999 ; Supovitz and Turner, 2000 ; Capps et al., 2012 ).A common criticism of professional development activities is that they are too often one-shot workshops with limited follow-up after the workshop activities (Darling-Hammond, 2005 ; Wei et al., 2010 ). The literature on teacher learning and professional development calls for professional development that is sustained over time, as the duration of professional development is related to the depth of teacher change (Shields et al., 1998 ; Weiss et al., 1998 ; Supovitz and Turner, 2000 ; Banilower et al., 2007 ). If the professional development program is too short in duration, teachers may dismiss the suggested practices or at best assimilate teaching strategies into their current repertoire with little substantive change (Tyack and Cuban, 1995 ; Coburn, 2004 ). For example, Supovitz and Turner (2000 ) found that sustained professional development (more than 80 h) was needed to create an investigative classroom culture in science, as opposed to small-scale changes in practices. Teachers need professional development that is interactive with their teaching practices; in other words, professional development programs should allow time for teachers to try out new practices, to obtain feedback on their teaching, and to reflect on these new practices. Not only is duration (total number of hours) of professional development important, but also the time span of the professional development experience (number of years across which professional hours are situated) to allow for multiple cycles of presentation and reflection on practices (Blumenfeld et al., 1991 ; Garet et al., 2001 ). Supovitz and Turner''s study (2000) suggests that it is more difficult to change classroom culture than teaching practices; the greatest changes in teaching practices occurred after 80 h of professional development, while changes in classroom investigative culture did not occur until after 160 h of professional development.Finally, research indicates that professional development that focuses on science content and how children learn is important in changing teaching practices (e.g., Corcoran, 1995 ; Desimone, 2009 ), particularly when the goal is the implementation of inquiry-like instruction designed to improve students’ conceptual understanding (Fennema et al., 1996 ; Cohen and Hill, 1998 ). The science content chosen for the professional development series described in this study was neuroscience. This content is relevant for both middle and high school science teachers and has direct connections to standards. It also is unique in that it encompasses material on the neurological basis for learning, thus allowing discussions about student learning to occur within both a scientific and pedagogical context. As a final note, it is rare for even a life science teacher to have taken any coursework in neuroscience. The inquiry-based lessons and experiments encountered by the teachers during the professional development provide an authentic learning experience, allowing teachers to truly inhabit the role of a learner in an inquiry-based setting.  相似文献   

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This article examines the validity of the Undergraduate Research Student Self-Assessment (URSSA), a survey used to evaluate undergraduate research (UR) programs. The underlying structure of the survey was assessed with confirmatory factor analysis; also examined were correlations between different average scores, score reliability, and matches between numerical and textual item responses. The study found that four components of the survey represent separate but related constructs for cognitive skills and affective learning gains derived from the UR experience. Average scores from item blocks formed reliable but moderate to highly correlated composite measures. Additionally, some questions about student learning gains (meant to assess individual learning) correlated to ratings of satisfaction with external aspects of the research experience. The pattern of correlation among individual items suggests that items asking students to rate external aspects of their environment were more like satisfaction ratings than items that directly ask about student skills attainment. Finally, survey items asking about student aspirations to attend graduate school in science reflected inflated estimates of the proportions of students who had actually decided on graduate education after their UR experiences. Recommendations for revisions to the survey include clarified item wording and increasing discrimination between item blocks through reorganization.Undergraduate research (UR) experiences have long been an important component of science education at universities and colleges but have received greater attention in recent years, as they have been identified as important ways to strengthen preparation for advanced study and work in the science fields, especially among students from underrepresented minority groups (Tsui, 2007 ; Kuh, 2008 ). UR internships provide students with the opportunity to conduct authentic research in laboratories with scientist mentors, as students help design projects, gather and analyze data, and write up and present findings (Laursen et al., 2010 ). The promised benefits of UR experiences include both increased skills and greater familiarity with how science is practiced (Russell et al., 2007 ). While students learn the basics of scientific methods and laboratory skills, they are also exposed to the culture and norms of science (Carlone and Johnson, 2007 ; Hunter et al., 2007 ; Lopatto, 2010 ). Students learn about the day-to-day world of practicing science and are introduced to how scientists design studies, collect and analyze data, and communicate their research. After participating in UR, students may make more informed decisions about their future, and some may be more likely to decide to pursue graduate education in science, technology, engineering, and mathematics (STEM) disciplines (Bauer and Bennett, 2003 ; Russell et al., 2007 ; Eagan et al. 2013 ).While UR experiences potentially have many benefits for undergraduate students, assessing these benefits is challenging (Laursen, 2015 ). Large-scale research-based evaluation of the effects of UR is limited by a range of methodological problems (Eagan et al., 2013 ). True experimental studies are almost impossible to implement, since random assignment of students into UR programs is both logistically and ethically impractical, while many simple comparisons between UR and non-UR groups of students suffer from noncomparable groups and limited generalizability (Maton and Hrabowski, 2004 ). Survey studies often rely on poorly developed measures and use nonrepresentative samples, and large-scale survey research usually requires complex statistical models to control for student self-selection into UR programs (Eagan et al., 2013 ). For smaller-scale program evaluation, evaluators also encounter a number of measurement problems. Because of the wide range of disciplines, research topics, and methods, common standardized tests assessing laboratory skills and understandings across these disciplines are difficult to find. While faculty at individual sites may directly assess products, presentations, and behavior using authentic assessments such as portfolios, rubrics, and performance assessments, these assessments can be time-consuming and not easily comparable with similar efforts at other laboratories (Stokking et al., 2004 ; Kuh et al., 2014 ). Additionally, the affective outcomes of UR are not readily tapped by direct academic assessment, as many of the benefits found for students in UR, such as motivation, enculturation, and self-efficacy, are not measured by tests or other assessments (Carlone and Johnson, 2007 ). Other instruments for assessing UR outcomes, such as Lopatto’s SURE (Lopatto, 2010 ), focus on these affective outcomes rather than direct assessments of skills and cognitive gains.The size of most UR programs also makes assessment difficult. Research Experiences for Undergraduates (REUs), one mechanism by which UR programs may be organized within an institution, are funded by the National Science Foundation (NSF), but unlike many other educational programs at NSF (e.g., TUES) that require fully funded evaluations with multiple sources of evidence (Frechtling, 2010 ), REUs are generally so small that they cannot typically support this type of evaluation unless multiple programs pool their resources to provide adequate assessment. Informal UR experiences, offered to students by individual faculty within their own laboratories, are often more common but are typically not coordinated across departments or institutions or accountable to a central office or agency for assessment. Partly toward this end, the Undergraduate Research Student Self-Assessment (URSSA) was developed as a common assessment instrument that can be compared across multiple UR sites within or across institutions. It is meant to be used as one source of assessment information about UR sites and their students.The current research examines the validity of the URSSA in the context of its use as a self-report survey for UR programs and laboratories. Because the survey has been taken by more than 3400 students, we can test some aspects of how the survey is structured and how it functions. Assessing the validity of the URSSA for its intended use is a process of testing hypotheses about how well the survey represents its intended content. This ongoing process (Messick, 1993 ; Kane, 2001 ) involves gathering evidence from a range of sources to learn whether validity claims are supported by evidence and whether the survey results can be used confidently in specific contexts. For the URSSA, our method of inquiry focuses on how the survey is used to assess consortia of REU sites. In this context, survey results are used for quality assurance and comparisons of average ratings over years and as general indicators of program success in encouraging students to pursue graduate science education and scientific careers. Our research questions focus on the meaning and reliability of “core indicators” used to track self-reported learning gains in four areas and the ability of numerical items to capture student aspirations for future plans to attend graduate school in the sciences.  相似文献   

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Although we agree with Theobold and Freeman (2014) that linear models are the most appropriate way in which to analyze assessment data, we show the importance of testing for interactions between covariates and factors.To the Editor:Recently, Theobald and Freeman (2014) reviewed approaches for measuring student learning gains in science, technology, engineering, and mathematics (STEM) education research. In their article, they highlighted the shortcomings of approaches such as raw change scores, normalized gain scores, normalized change scores, and effect sizes when students are not randomly assigned to classes based on the different pedagogies that are being compared. As an alternative, they propose using linear regression models in which characteristics of students, such as pretest scores, are included as independent variables in addition to treatments. Linear models that include both continuous and categorical independent variables are often termed analysis of covariance (ANCOVA) models. The approach of using ANCOVA to control for differences in students among treatments groups has been suggested previously by Weber (2009) . We largely agree with Theobald and Freeman (2014) and Weber (2009) that ANCOVA models are an appropriate method for situations in which students cannot be randomly assigned to treatments and controls. However, in describing how to implement linear regression models to examine student learning gains, Theobald and Freeman (2014) ignore a fundamental assumption of ANCOVA.ANCOVA assumes homogeneity of slopes (McDonald, 2009 ; Sokal and Rohlf, 2011 ). In other words, the slope of the relationship between the covariate (e.g., pretest score) and the dependent variable (e.g., posttest score) is the same for the treatment group and the control. This assumption is a strict assumption of ANCOVA in that violations of this assumption can result in incorrect conclusions (Engqvist, 2005 ). For example, in Figure 1, both pretest score and treatment have statistically significant main effects in a linear model with only pretest score (F(1, 97) = 25.6, p < 0.001) and treatment (F(1, 97) = 42.6, p < 0.01) as independent variables. Therefore, we would conclude that all students in the class with pedagogical innovation had significantly greater posttest scores than those students in the control class for a given pretest score. Furthermore, we would conclude that the pedagogical innovation led to the same increase in score for all students in the treatment class, independent of their pretest scores. Clearly, neither of these conclusions would be justified.Researchers must first test the assumption of the homogeneity of slopes by including an interaction term (covariate × treatment) in their linear model (McDonald, 2009 ; Weber 2009 ; Sokal and Rohlf, 2011 ). For example, if we measured student achievement in two courses with different instructional approaches in a typical pretest/posttest design, then the interaction between students’ pretest scores and the type of instruction must be considered, because the instruction may have a different effect for high- versus low-achieving students. If multiple covariates are included in the linear model (see Equation 1 in Theobald and Freeman, 2014 ), then interaction terms need to be included for each of the covariates in the model. If the interaction term is statistically significant, this suggests that the relationship between the covariate and the dependent variable is different for each treatment group (F(1, 96) = 25.1, p < 0.001; Figure 1). As a result, the effect of the treatment will depend on the value of the covariate, and universal statements about the effect of the treatment are not appropriate (Engqvist, 2005 ). If the interaction term is not statistically significant, it should be removed from the model and the analysis rerun without the interaction term. Failure to remove an interaction term that was not statistically significant also can lead to an incorrect conclusion (Engqvist, 2005 ). Whether there are statistically significant interactions between the “treatment” and the covariates in the data set used by Theobald and Freeman (2014) is unclear.Open in a separate windowFigure 1.Simulated data to demonstrate heterogeneity of slopes. Pretest values were generated from random normal distributions with mean = 59.8 (SD = 18.1) for the treatment course and mean = 59.3 (SD = 17.0) for the control course, based on values given in Theobald and Freeman (2014) . For the treatment course, posttest values were calculated using the formula posttesti = 80 + 0.1 × pre-testi + Ɛi, where Ɛi was selected from a random normal distribution with mean = 0 (SD = 10). For the control course, posttest values were calculated using the formula posttesti = 42 + 0.5 × pre-testi + Ɛi, where Ɛi was selected from a random normal distribution with mean = 0 (SD = 10). n = 50 for both courses.In addition to being a strict assumption of ANCOVA, testing for homogeneity of slopes in a linear model is important in STEM education research, as slopes are likely heterogeneous for several reasons. First, for many instruments used in STEM education research, high-achieving students score high on the pretest. As a result, their ability to improve is limited due to the ceiling effect, and differences between treatment and control groups in posttest scores are likely to be minimal (Figure 1). In contrast, low-achieving students have a greater opportunity to change their scores between their pretest and posttest. Second, pedagogical innovations are more likely to have a greater impact on the learning of lower-performing students than higher-performing students. For example, Beck and Blumer (2012) found statistically greater gains in student confidence and scientific reasoning skills for students in the lowest quartile as compared with students in the highest quartile on pretest assessments in inquiry-based laboratory courses.Theobald and Freeman (2014, p. 47) note that “regression models can also include interaction terms that test whether the intervention has a differential impact on different types of students.” Yet, we argue that these terms must be included and only should be excluded if they are not statistically significant.  相似文献   

10.
The scale and importance of Vision and Change in Undergraduate Biology Education: A Call to Action challenges us to ask fundamental questions about widespread transformation of college biology instruction. I propose that we have clarified the “vision” but lack research-based models and evidence needed to guide the “change.” To support this claim, I focus on several key topics, including evidence about effective use of active-teaching pedagogy by typical faculty and whether certain programs improve students’ understanding of the Vision and Change core concepts. Program evaluation is especially problematic. While current education research and theory should inform evaluation, several prominent biology faculty–development programs continue to rely on self-reporting by faculty and students. Science, technology, engineering, and mathematics (STEM) faculty-development overviews can guide program design. Such studies highlight viewing faculty members as collaborators, embedding rewards faculty value, and characteristics of effective faculty-development learning communities. A recent National Research Council report on discipline-based STEM education research emphasizes the need for long-term faculty development and deep conceptual change in teaching and learning as the basis for genuine transformation of college instruction. Despite the progress evident in Vision and Change, forward momentum will likely be limited, because we lack evidence-based, reliable models for actually realizing the desired “change.”
All members of the biology academic community should be committed to creating, using, assessing, and disseminating effective practices in teaching and learning and in building a true community of scholars. (American Association for the Advancement of Science [AAAS], 2011 , p. 49)
Realizing the “vision” in Vision and Change in Undergraduate Biology Education (Vision and Change; AAAS, 2011 ) is an enormous undertaking for the biology education community, and the scale and critical importance of this challenge prompts us to ask fundamental questions about widespread transformation of college biology teaching and learning. For example, Vision and Change reflects the consensus that active teaching enhances the learning of biology. However, what is known about widespread application of effective active-teaching pedagogy and how it may differ across institutional and classroom settings or with the depth of pedagogical understanding a biology faculty member may have? More broadly, what is the research base concerning higher education biology faculty–development programs, especially designs that lead to real change in classroom teaching? Has the develop-and-disseminate approach favored by the National Science Foundation''s (NSF) Division of Undergraduate Education (Dancy and Henderson, 2007 ) been generally effective? Can we directly apply outcomes from faculty-development programs in other science, technology, engineering, and mathematics (STEM) disciplines or is teaching college biology unique in important ways? In other words, if we intend to use Vision and Change as the basis for widespread transformation of biology instruction, is there a good deal of scholarly literature about how to help faculty make the endorsed changes or is this research base lacking?In the context of Vision and Change, in this essay I focus on a few key topics relevant to broad-scale faculty development, highlighting the extent and quality of the research base for it. My intention is to reveal numerous issues that may well inhibit forward momentum toward real transformation of college-level biology teaching and learning. Some are quite fundamental, such as ongoing dependence on less reliable assessment approaches for professional-development programs and mixed success of active-learning pedagogy by broad populations of biology faculty. I also offer specific suggestions to improve and build on identified issues.At the center of my inquiry is the faculty member. Following the definition used by the Professional and Organizational Development Network in Higher Education (www.podnetwork.org), I use “faculty development” to indicate programs that emphasize the individual faculty member as teacher (e.g., his or her skill in the classroom), scholar/professional (publishing, college/university service), and person (time constraints, self-confidence). Of course, faculty members work within particular departments and institutions, and these environments are clearly critical as well (Stark et al., 2002 ). Consequently, in addition to focusing on the individual, faculty-development programs may also consider organizational structure (such as administrators and criteria for reappointment and tenure) and instructional development (the overall curriculum, who teaches particular courses). In fact, Diamond (2002) emphasizes that the three areas of effort (individual, organizational, instructional) should complement one another in faculty-development programs. The scope of the numerous factors impacting higher education biology instruction is a realistic reminder about the complexity and challenge of the second half of the Vision and Change endeavor.This essay is organized around specific topics meant to be representative and to illustrate the state of the art of widespread (beyond a limited number of courses and institutions) professional development for biology faculty. The first two sections focus on active teaching and biology students’ conceptual understanding, respectively. The third section concerns important elements that have been identified as critical for effective STEM faculty-development programs.  相似文献   

11.
Testing within the science classroom is commonly used for both formative and summative assessment purposes to let the student and the instructor gauge progress toward learning goals. Research within cognitive science suggests, however, that testing can also be a learning event. We present summaries of studies that suggest that repeated retrieval can enhance long-term learning in a laboratory setting; various testing formats can promote learning; feedback enhances the benefits of testing; testing can potentiate further study; and benefits of testing are not limited to rote memory. Most of these studies were performed in a laboratory environment, so we also present summaries of experiments suggesting that the benefits of testing can extend to the classroom. Finally, we suggest opportunities that these observations raise for the classroom and for further research.Almost all science classes incorporate testing. Tests are most commonly used as summative assessment tools meant to gauge whether students have achieved the learning objectives of the course. They are sometimes also used as formative assessment tools—often in the form of low-stakes weekly or daily quizzes—to give students and faculty members a sense of students’ progression toward those learning objectives. Occasionally, tests are also used as diagnostic tools, to determine students’ preexisting conceptions or skills relevant to an upcoming subject. Rarely, however, do we think of tests as learning tools. We may acknowledge that testing promotes student learning, but we often attribute this effect to the studying students do to prepare for the test. And yet, one of the most consistent findings in cognitive psychology is that testing leads to increased retention more than studying alone does (Roediger and Butler, 2011 ; Roediger and Pyc, 2012 ). This effect can be enhanced when students receive feedback for failed tests and can be observed for both short-term and long-term retention. There is some evidence that testing not only improves student memory of the tested information but also ability to remember related information. Finally, testing appears to potentiate further study, allowing students to gain more from study periods that follow a test. Given the potential power of testing as a tool to promote learning, we should consider how to incorporate tests into our courses not only to gauge students’ learning, but also to promote that learning (Klionsky, 2008 ).We provide six observations about the effects of testing from the cognitive psychology literature, summarizing key studies that led to these conclusions (see
StudyResearch question(s)ConclusionLength of delay before final testStudy participants
Repeated retrieval enhances long-term retention in a laboratory setting
“Test-enhanced learning: taking memory tests improves long-term retention” (Roediger and Karpicke, 2006a) Is a testing effect observed in educationally relevant conditions? Is the benefit of testing greater than the benefit of restudy? Do multiple tests produce a greater effect than a single test?Testing improved retention significantly more than restudy in delayed tests. Multiple tests provided greater benefit than a single test.Experiment 1: 2 d; 1 wk Experiment 2: 1 wkUndergraduates ages 18–24, Washington University
“Retrieval practice with short-answer, multiple-choice, and hybrid tests” (Smith and Karpicke, 2014) What effect does the type of question presented in retrieval practice have on long-term retention?Retrieval practice with multiple-choice, free-response, and hybrid formats improved students’ performance on a final, delayed test taken 1 wk later when compared with a no-retrieval control. The effect was observed for both questions that required only recall and those that required inference. Hybrid questions provided an advantage when the final test had a short-answer format.1 wkUndergraduates, Purdue University
“Retrieval practice produces more learning that elaborative studying with concept mapping” (Karpicke and Blunt, 2011) What is the effect of retrieval practice on learning relative to elaborative study using a concept map?Students in the retrieval-practice condition had greater gains in meaningful learning compared with those who used elaborative concept mapping as a learning tool.1 wkUndergraduates
Various testing formats can enhance learning
“Retrieval practice with short-answer, multiple-choice, and hybrid tests” (Smith and Karpicke, 2014) See above.See above.See above.See above.
“Test format and corrective feedback modify the effect of testing on long-term retention” (Kang et al., 2007) What effect does the type of question used for retrieval practice have on retention? Does feedback have an effect on retention for different types of questions?When no feedback was given, the difference in long-term retention between short-answer and multiple-choice questions was insignificant. When feedback was provided, short-answer questions were slightly more beneficial.3 dUndergraduates, Washington University psychology subjects’ pool
“The persisting benefits of using multiple-choice tests as learning events” (Little and Bjork, 2012) What effect does question format have on retention of information previously tested and related information not included in retrieval practice?Both cued-recall and multiple-choice questions improved recall compared with the no-test control. However, multiple-choice questions improved recall more than cued-recall questions for information not included in the retrieval practice, both after a 5-min and a 48-h delay.48 hUndergraduates, University of California, Los Angeles
Feedback enhances benefits of testing
“Feedback enhances positive effects and reduces the negative effects of multiple-choice testing” (Butler and Roediger, 2008) What effect does feedback on multiple-choice tests have on long-term retention of information?Feedback improved retention on a final cued-recall test. Delayed feedback resulted in better final performance than immediate feedback, though both showed benefits compared with no feedback. The final test occurred 1 wk after the initial test.1 wkUndergraduate psychology students, Washington University
“Correcting a metacognitive error: feedback increases retention of low-confidence responses” (Butler et al., 2008) What role does feedback play in retrieval practice? Can it correct metacognitive errors as well as memory errors?Both initially correct and incorrect answers were benefited by feedback, but low-confidence answers were most benefited by feedback.5 minUndergraduate psychology students, Washington University
Learning is not limited to rote memory
“Retrieval practice produces more learning than elaborative study with concept mapping” (Karpicke and Blunt, 2011) What is the effect of retrieval practice on learning relative to elaborative study using a concept map? Does retrieval practice improve students’ ability to perform higher-order cognitive activities (i.e., building a concept map) as well as simple recall tasks?Compared with elaborative study using concept mapping, retrieval practice improved students’ performance both on final tests that required short answers and final tests that required concept map production. See also earlier entry for this study.1 wkUndergraduates
“Retrieval practice with short-answer, multiple-choice, and hybrid tests” (Smith and Karpicke, 2014) See above.See above.See above.See above.
“Repeated testing produces superior transfer of learning relative to repeated studying” (Butler, 2010) Does test-enhanced learning promote transfer of facts and concepts from one domain to another?Testing improved retention and increased transfer of information from one domain to another through test questions that required factual or conceptual recall and inferential questions that required transfer.1 wkUndergraduate psychology students, Washington University
Testing potentiates further study
“Pretesting with multiple-choice questions facilitates learning” (Little and Bjork, 2011) Does pretesting using multiple-choice questions improve performance on a later test? Is an effect observed only for pretested information or also for related, previously untested information?A multiple-choice pretest improved performance on a final test, both for information that was included on the pretest and related information.1 wkUndergraduates, University of California, Los Angeles
“The interim test effect: testing prior material can facilitate the learning of new material” (Wissman et al., 2011) Does an interim test over previously learned material improve retention of subsequently learned material?Interim testing improves recall on a final test for information taught before and after the interim test.No delayUndergraduates, Kent State University
The benefits of testing appear to extend to the classroom
“The exam-a-day procedure improves performance in psychology classes” (Leeming, 2002) What effect does a daily exam have on retention at the end of the semester?Students who took a daily exam in an undergraduate psychology class scored higher on a retention test at the end of the course and had higher average grades than students who only took unit tests.One semesterUndergraduates enrolled in Summer term of Introductory Psychology, University of Memphis
“Repeated testing improves long-term retention relative to repeated study: a randomized controlled trial” (Larsen et al., 2009) Does repeated testing improve long-term retention in a real learning environment?In a study with medical residents, repeated testing with feedback improved retention more than repeated study for a final recall test 6 mo later.6 moResidents from Pediatrics and Emergency Medicine programs, Washington University
“Retrieving essential material at the end of lectures improves performance on statistics exams” (Lyle and Crawford, 2011) What effect does daily recall practice using the PUREMEM method have on course exam scores?In an undergraduate psychology course, students using the PUREMEM method had higher exams scores than students taught with traditional lectures, assessed by four noncumulative exams spaced evenly throughout the semester.∼3.5 wkUndergraduates enrolled in either of two consecutive years of Statistics for Psychology, University of Louisville
“Using quizzes to enhance summative-assessment performance in a web-based class: an experimental study” (McDaniel et al., 2012) What effects do online testing resources have on retention of information in an online undergraduate neuroscience course?Both multiple-choice and short-answer quiz questions improved retention and improved scores on the final exam for questions identical to those on the weekly quizzes and those that were related but not identical.15 wkUndergraduates enrolled in Web-based brain and behavior course
“Increasing student success using online quizzing in introductory (majors) biology” (Orr and Foster, 2013) What effect do required pre-exam quizzes have on final exam scores for students in an introductory (major) biology course?Students were required to complete 10 pre-exam quizzes throughout the semester. The scores of students who completed all of the quizzes or none of the quizzes were compared. Students of all abilities who completed all of the pre-exam quizzes had higher average exam scores than those who completed none.One semesterCommunity college students enrolled in an introductory biology course for majors
“Teaching students how to study: a workshop on information processing and self-testing helps students learn” (Stanger-Hall et al., 2011) What effect does a self-testing exercise done in a workshop have on final exam questions covering the same topic used in the workshop?Students who participated in the retrieval-practice workshop performed better on the exam questions related to the material covered in the workshop activity. However, there was no difference in overall performance on the exam between the two groups.10 wkUndergraduate students in a introductory biology class
Open in a separate window  相似文献   

12.
High School Students’ Learning and Perceptions of Phylogenetics of Flowering Plants     
Julie R. Bokor  Jacob B. Landis  Kent J. Crippen 《CBE life sciences education》2014,13(4):653-665
Basic phylogenetics and associated “tree thinking” are often minimized or excluded in formal school curricula. Informal settings provide an opportunity to extend the K–12 school curriculum, introducing learners to new ideas, piquing interest in science, and fostering scientific literacy. Similarly, university researchers participating in science, technology, engineering, and mathematics (STEM) outreach activities increase awareness of college and career options and highlight interdisciplinary fields of science research and augment the science curriculum. To aid in this effort, we designed a 6-h module in which students utilized 12 flowering plant species to generate morphological and molecular phylogenies using biological techniques and bioinformatics tools. The phylogenetics module was implemented with 83 high school students during a weeklong university STEM immersion program and aimed to increase student understanding of phylogenetics and coevolution of plants and pollinators. Student response reflected positive engagement and learning gains as evidenced through content assessments, program evaluation surveys, and program artifacts. We present the results of the first year of implementation and discuss modifications for future use in our immersion programs as well as in multiple course settings at the high school and undergraduate levels.
Just as beginning students in geography need to be taught how to read maps, so beginning students in biology should be taught how to read trees and to understand what trees communicate. O’Hara (1997 , p. 327)
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13.
A Portal into Biology Education: An Annotated List of Commonly Encountered Terms     
Sarah Miller  Kimberly D. Tanner 《CBE life sciences education》2015,14(2)
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14.
From Vision to Change: Educational Initiatives and Research at the Intersection of Physics and Biology     
Eric Brewe  Nancy J. Pelaez  Todd J. Cooke 《CBE life sciences education》2013,12(2):117-119
In this editorial we link the articles published in this Special Issue with the framework from Vision and Change and summarize findings from the editorial process of assembling the Special Issue.The authors of Vision and Change (American Association for the Advancement of Science [AAAS], 2011 ) issued the following call to action to biologists, physicists, chemists, and mathematicians:
To ensure that all students graduate with a basic level of scientific literacy and meet the challenges raised in Bio 2010: Transforming Undergraduate Education for Future Research Biologists (2003), Scientific Foundations for Future Physicians: Report of the AAMC-HHMI Committee (2009), A New Biology for the 21st Century (2009), and similar reports, biologists, physicists, chemists, and mathematicians need to look thoughtfully at ways they can introduce interdisciplinary approaches into their gateway courses. (AAAS, 2011 , p 54)
The articles that comprise this special issue of CBE—Life Sciences Education (LSE) take important steps toward responding to this call by describing teaching and learning at the intersection of biology and physics. Broadly defined, the work aims to encourage the development of genuine interdisciplinary understanding, or “the capacity to integrate knowledge and modes of thinking in two or more disciplines or established areas of expertise to produce a cognitive advancement … in ways that would have been impossible or unlikely through single disciplinary means” (Boix Mansilla and Duraisingh, 2007 , p. 219). Indeed, many of the most exciting recent breakthroughs in the life sciences have occurred at the intersection of these established disciplines. Physical laws help to predict, describe, and explain biological phenomena occurring at molecular to ecosystem levels, and the development of new physical tools helps to visualize these phenomena in new and informative ways. Thus, the Vision and Change report stresses the urgency for undergraduate biology and physics educators to develop, assess, and revise content materials, pedagogical strategies, and epistemological perspectives for encouraging student learning in interdisciplinary biology and physics classes.We received more than 50 abstracts in response to the call for this special issue, and we are pleased to publish 10 Articles, four Essays, and eight Features reflecting the state of educational transformation at the intersection of biology and physics. Several articles describe integration of physics into biology curriculum or biology into physics curriculum that goes beyond simple provision of examples from the respective disciplines (e.g., Batiza et al., Christensen et al., Svoboda Gouvea et al., O’Shea et al., Thompson et al., Breckler et al.). A number of articles address cross-cutting themes, such as problem solving (e.g., Hoskinson et al.) and energy (e.g., Cooper and Klymkowsky, Svoboda Gouvea et al.), the application of mathematical laws to biological phenomena (e.g., Redish and Cooke), epistemology (e.g., Watkins and Elby), and assessment as a powerful tool for driving curriculum change, in this case the integration of physics and biological thinking (e.g., Svoboda Gouvea et al., Momsen et al., Thompson et al.). Other articles reflect research crossing disciplinary boundaries to introduce research approaches (e.g., Watkins and Elby, Momsen et al.) or innovative curriculum models (e.g., Manthey and Brewe, Donovan et al., Thompson et al.) to help students develop reasoning strategies that move beyond traditional disciplinary boundaries. The Hillborn and Friedlander essay highlights potential impacts of cross-disciplinary collaboration in education on the revised Medical College Admission Test.We were pleased by the number of articles coauthored by physicists and biologists working in teams to examine and recommend new directions for the future of biology education. These teams brought a richness and depth of knowledge in both disciplines that made it possible to move instruction and research forward at the intersection of the disciplines. Together, these articles start to provide the evidence base for responding to the calls for interdisciplinary teaching and learning. Further, they provide opportunities to compare and contrast education and epistemologies in biology and physics, allowing for more informed integration of knowledge from these disciplines.  相似文献   

15.
Recent Research in Science Teaching and Learning     
Deborah Allen 《CBE life sciences education》2014,13(4):584-586
This feature is designed to point CBE---Life Sciences Education readers to current articles of interest in life sciences education as well as more general and noteworthy publications in education research.This feature is designed to point CBE—Life Sciences Education readers to current articles of interest in life sciences education as well as more general and noteworthy publications in education research. URLs are provided for the abstracts or full text of articles. For articles listed as “Abstract available,” full text may be accessible at the indicated URL for readers whose institutions subscribe to the corresponding journal.
  • 1. Freeman S, Eddy SL, McDonough M, Smith MK, Okoroafor N, Jordt H, Wenderoth MP (2014). Active learning increases student performance in science, engineering, and mathematics. Proc Natl Acad Sci USA 111, 8410–8415. [Abstract available at www.pnas.org/content/111/23/8410.abstract]
Online publication of this meta-analysis last spring no doubt launched a legion of local and national conversations about how science is best taught—as the authors state the essential issue, “Should we ask or should we tell?” To assess the relative effectiveness of active-learning (asking) versus lecture-based (telling) methods in college-level science, technology, engineering, and mathematics (STEM) classes, the authors scoured the published and unpublished literature for studies that performed a side-by-side comparison of the two general types of methods. Using five predetermined criteria for admission to the study (described fully in the materials and methods section), at least two independent coders examined each potentially eligible paper to winnow down the number of eligible studies from 642 to 225. The working definition of what constitutes active learning (used to determine potential eligibility) was obtained from distilling definitions written by 338 seminar attendees; what constitutes lecture was defined as “continuous exposition by the teacher” (quoted from Bligh, 2000 ). The eligible studies were situated in introductory and upper-division courses from a full range of enrollment sizes and multiple STEM disciplines and included majors and nonmajors as participants. The frequency of use and types of active-learning methodologies described in the 225 eligible studies varied widely.Quantitative analysis of the eligible studies focused on comparison of two outcome variables: 1) scores on identical or formally equivalent examinations and 2) failure rates (receipt of a “D” or “F” grade or withdrawal from the course). Major findings were that student performance on exams and other assessments (such as concept inventories) was nearly half an SD higher in active-learning versus lecture courses, with an effect size (standardized mean weighted difference) of 0.47. Analyses also revealed that average failure rates were 55% higher for students in the lecture courses than in courses with active learning. Heterogeneity analyses indicated that 1) there were no statistically significant differences in outcomes with respect to disciplines; 2) effect sizes were lower when instructor-generated exams were used versus concept inventories with both types of courses (perhaps because concept inventories tend to require more higher-order thinking skills); 3) effect sizes were not significantly different in nonmajors versus majors courses or in lower versus upper-division courses; and 4) although active learning had the greatest positive effect in smaller-enrollment courses, effect sizes were higher with active learning at all enrollment sizes. Two types of analyses, calculation of fail-safe numbers and funnel plots, supported a lack of publication bias (tendency to not publish studies with low effect sizes). Finally, the authors demonstrated that there were no statistically significant differences in effect sizes despite variation in the quality of the controls on instructor and student equivalence, supporting the important conclusion that the differences in effectiveness between the two methods were not instructor dependent.In one of the more compelling sections of this meta-analysis, the authors translated the relatively dry numbers resulting from statistical comparisons to potential impacts on the lives of the students taking STEM courses. For example, for the 29,300 students reported for the lecture treatments across all students, the average difference in failure rates (21.8% in active learning vs. 33.8% with lecture) suggests that 3516 fewer students would have failed if enrolled in an active-learning course. This and other implications for the more beneficial impact of active learning on STEM students led the authors to state, “If the experiments analyzed here had been conducted as randomized controlled trials of medical interventions, they may have been stopped for benefit.” That is, the control group condition would have been halted because of the clear, beneficial effects of the treatment. The authors conclude by suggesting additional important implications for future undergraduate STEM education research. It may no longer be justified to conduct more “first-generation” research comparing active-learning approaches with traditional lecture; rather, for greater impact on course design, second-generation researchers should focus on what types and intensities of exposure to active learning are most effective for different students, instructors, and topics.This provocative commentary by Carl Weiman highlights the major findings reported in the Proceedings of the National Academy of Sciences by Freeman et al. (2014) and underscores the implications. The graphical representations displaying the key data on effect sizes and failure rates presented in the Freeman et al. meta-analysis are redrawn in the commentary in a way that is likely to be more familiar to the typical reader, making the differences in outcomes for active learning versus lecture appear more striking. Weiman concludes by elaborating on the important implications of the meta-analysis for college-level STEM educators and administrators, suggesting that it “makes a powerful case that any college or university that is teaching its STEM courses by traditional lectures is providing an inferior education to its students. One hopes that it will inspire administrators to start paying attention to the teaching methods used in their classrooms … establishing accountability for using active-learning methods.”National societies, committee reports, and accrediting bodies recommend that engineering curricula be designed to prepare future engineers for the complex interdisciplinary nature of the field and for the multitude of skills and perspectives they will need to be successful practitioners. The authors posit that case-based instruction, with its emphasis on honing skills in solving authentic, interdisciplinary, and ill-defined problems, aligns well with these recommendations. However, the methodology is still relatively underutilized, and its effectiveness is underexamined. This article describes a study designed to advance these issues by comparing lecture- and case-based methods within the same offering of a 72-student, upper-level, required course in mechanical engineering.The study used a within-subjects, posttest only, A-B-A-B research design across four key course topics. That is, two lecture-based modules (the A or baseline phases) alternated with case-based modules (the B or treatment phases). Following each module, students responded to open-response quiz questions and a survey about learning and engagement (adapted from the Student Assessment of Learning Gains instrument). The quiz questions assessed ability to apply knowledge to problem solving (so-called “traditional” questions) and ability to explain the concepts that were used (“conceptual” questions). This study design had the advantage that the same students experienced both the baseline and treatment conditions twice. The authors describe in detail the pedagogical approaches used in both sets of the A and B phases.The quizzes were scored by independent raters (with high interrater reliability) on a 0–3 scale; scores were analyzed using appropriate statistical methods. Survey items were analyzed using a principal-components factor analysis; composite scores were generated for a learning confidence factor and an engagement–connections factor. Analyses revealed that the two pedagogical approaches had similar outcomes with respect to the traditional questions, but conceptual understanding scores (indicating better understanding of the concepts that were applied to problem solving) were significantly higher for the case-based modules. Students reported that they appreciated how cases were better than lecture in helping them make connections to real-world concerns and see the relevance of what they were learning, but there were no significant differences in students’ perceptions of their learning gains in the case-based versus the lecture modules. The authors note that many studies have likewise demonstrated that students’ perceptions of their learning gains in more learner-centered courses are often not accurate reflections of the actual learning outcomes.The authors conclude that while these results are promising indications of the effectiveness of case-based instruction in engineering curricula, the studies need to be replicated across a number of semesters and in different engineering disciplines and extended to assess the long-term effect of case-based instruction on students’ ability to remember and apply their knowledge.Although this study was limited to an engineering context, the case-based methodologies and research design seem well-suited for use in action research in other disciplines.Well-documented challenges to conceptual change faced by students of evolution include the necessity of unseating existing naïve theories (such as natural selection having purposiveness), having the ability to view the complex and emergent nature of evolutionary processes through systems-type thinking, and being able to see the connections between evolutionary content learned in the classroom and everyday life events that can facilitate appreciation of its importance and motivate learning. To help students meet these challenges, the authors adapted a pedagogical model called Teaching for Transformative Experiences in Science (TTES) in the course of instruction on six major concepts in evolutionary biology. This article reports on a comparison of the effectiveness of TTES approaches in fostering conceptual change and positive affect with that of instruction enhanced with use of refutational texts (RT). Use of RTs to promote conceptual change, a strategy with documented effectiveness, entails first stating a misconception (the term used by the authors), then explicitly refuting it by elaborating on a scientific explanation. By contrast, the TTES model promotes teaching that fosters transformative learning experiences—teaching in which instructors 1) place the content in a context allows the students to see its utility or experiential value; 2) model their own transformative experiences in learning course concepts; and 3) scaffold a process that allows students to rethink or “resee” a concept from the perspective of their previous, related life experiences.The authors designed the study to address three questions relevant to the comparison of the two approaches: would the TTES group (vs. the RT group) demonstrate or report 1) greater conceptual change, 2) higher levels of transformative experience, and 3) differences in topic emotions (more positive affect) related to learning about evolution? The study used three survey instruments, one that measured the types and depth of students’ transformative experiences (the Transformative Experience Survey, adapted from Pugh et al., 2010 ), another that assessed conceptual knowledge (Evolutionary Reasoning Scale; Shulman, 2006 ), and a third that evaluated the emotional reactions of students to the evolution content they were learning (Evolution Emotions Survey, derived from Broughton et al., 2011 ). In addition to Likert-scale items, the Transformative Experience Survey contained three open-ended response questions; the responses were scored by two independent raters using a coding scheme for degree of out-of-school engagement. The authors provide additional detail about the nuances of what these instruments were designed to measure and their scoring schemes and include the instruments in the appendices. The Evolutionary Reasoning Scale and the Evolution Emotions survey were administered as both pre- and posttests, and the Transformative Experience survey was administered only at the end of the intervention. The treatment (TTES, n = 28) and comparison (RT, n = 27) groups were not significantly different with respect to all measured demographic variables and the number of high school or college-level science courses taken.Briefly, the evolutionary biology learning experience that participants were exposed to was 3 d in duration for both the treatment and comparison groups. On day 1, the instructor (the same person for both groups) gave a PowerPoint lecture on the same six evolutionary concepts, with illustrative examples. For the treatment group only, the instructor drew from his own transformative experiences in connection with the illustrative examples, describing how he used the concepts, what their value was to him, and how each had expanded his understanding and perception of evolution. On days 2 and 3 for the treatment group, the students and instructor engaged in whole-class discussions about their everyday experiences with evolution concepts (and related misconceptions) and their usefulness; the instructor scaffolded various “reseeing” experiences throughout the discussions. For the comparison group, misconceptions and refutations were addressed in the course of the day 1 lecture, and on days 2 and 3, the participants read refutational texts and then took part in discussions of the texts led by the instructor.Survey results and accompanying statistical analyses indicated that both groups exhibited gains (with significant t statistics) in understanding of the evolution concepts as measured by the Evolutionary Reasoning Scale (Shulman, 2006 ). However, the gains were greater for the treatment (TTES) group: effect size, reported as a value for eta-squared, η2, equaled 0.29. The authors point out by way of context for this outcome that use of RTs, along with follow-up discussions that contrast misconceptions with scientific explanations, has been previously shown to be effective in promoting conceptual change; thus, the comparison was with a well-regarded methodology. Additionally, the Transformation Experience survey findings indicated higher levels of transformative experience for the TTES group participants; they more extensively reported that the concepts had everyday value and meaning and expanded their perspectives. The TTES group alone showed pre- to posttest gains in enjoyment while learning about evolution, a positive emotion that may have classroom implications in terms of receptivity to learning about evolution and willingness to continue study in this and related fields.The authors conclude that the TTES model can effectively engage students in transformative experiences in ways that can facilitate conceptual change in content areas in which that change is difficult to achieve. In discussing possible limitations of the study, they note in particular that the predominance of female study participants (71% of the total) argues for its replication with a more diverse sample.I invite readers to suggest current themes or articles of interest in life sciences education, as well as influential papers published in the more distant past or in the broader field of education research, to be featured in Current Insights. Please send any suggestions to Deborah Allen (ude.ledu@nellaed).  相似文献   

16.
Problem- and Case-Based Learning in Science: An Introduction to Distinctions,Values, and Outcomes     
Douglas Allchin 《CBE life sciences education》2013,12(3):364-372
Case-based learning and problem-based learning have demonstrated great promise in reforming science education. Yet an instructor, in newly considering this suite of interrelated pedagogical strategies, faces a number of important instructional choices. Different features and their related values and learning outcomes are profiled here, including: the level of student autonomy; instructional focus on content, skills development, or nature-of-science understanding; the role of history, or known outcomes; scope, clarity, and authenticity of problems provided to students; extent of collaboration; complexity, in terms of number of interpretive perspectives; and, perhaps most importantly, the role of applying versus generating knowledge.
A leader who gives trust earns trust.His profile is low, his words measured.His work done well, all proclaim,“Look what we’ve accomplished!”—Lao Tsu, Tao Te Ching
Problem-based learning (PBL) and case-based learning (CBL) are at least as old as apprenticeship among craftsmen. One can envision the student of metals at the smelting furnace, the student of herbal remedies at the plant collector''s side, or the student of navigation beside the helm. In recent years, however, PBL and CBL have emerged as powerful teaching tools in reforming science education. Most notably, these approaches exhibit key features advocated by educational researchers. First, both are fundamentally student-centered, acknowledging the importance of actively engaging students in their own learning. As the responsibility for learning shifts toward students, the role of the instructor also shifts, from the conventional authority who dispenses final-form knowledge to an expert guide, who motivates and facilitates the process of learning, while promoting the individual development of learning skills. The efforts of an ideal teacher may well be hidden. As Lao Tsu suggested centuries ago, educational achievement is measured by what a learner learns more than by what the teacher teaches.Second, in orienting more toward student perspectives and motivations, CBL and PBL tend to focus on concrete, specific occasions—cases or problems—wherein the target knowledge is relevant. Contextualizing the learning contributes both to student motivation and to the making of meaning (construed by many educators as central to functional memory and effective learning). The cases and problems are not merely supplemental illustrations or peripheral sidebars, but function centrally as the very occasion for learning. This style of learning resonates with views of cognitive scientists that our minds reason effectively through analogy and models, as much as through the interpretation and application of general, abstract principles.A third feature, and perhaps the most transformative, is the potential of PBL and CBL to contribute to the development of thinking skills and an understanding of the nature of science, beyond the conventional conceptual content. As students work on cases or problems, they typically exercise and hone skills in research, analysis, interpretation, and creative thinking. In addition to benefiting from practice, students may also reflect explicitly on their experience and thereby deepen their understanding of scientific practices. But such lessons do not emerge automatically. The instructor must make deliberate choices and design activities mindfully to support this aim.In these three ways, PBL and CBL have proven valuable in many settings and hold promise more widely. An instructor first venturing into the realm of CBL and PBL, however, may easily be overwhelmed by the variety of approaches and the occasional contradictions among them. The literature is vast and includes sometimes conflicting claims about appropriate or ideal methods. This paper aims to introduce some of the key dimensions and to invite reflection about the respective values and deficits of various alternatives. It hopes to inform pedagogical choices about learning objectives and foster corresponding clarity in classroom practice. It also hopes, indirectly, to promote clarity on values and learning outcomes among current practitioners and in educational research and to provide perspective on the discord among advocates of specific approaches.1The first two sections below introduce CBL and PBL, respectively, as instructional strategies reflecting certain values. (A teacher might well adopt both simultaneously.) Beyond these basics, there are many dimensions or distinctions to consider, addressed in successive sections (and summarized in 2 In addition, PBL gained recognition largely from applications in professional education—medical, business, and law schools (Butler et al., 2005 ). These instructional contexts tend to emphasize training. Contemporary science education, by contrast, tends to highlight student-based inquiry and understanding of scientific practices (National Research Council, 2012 ). The original approaches, as models, may need adapting. Most notably, the difference in context, between learning how to apply knowledge and learning how knowledge is generated, can be critical, as described below. The principles surveyed here can help guide the teacher in crafting an appropriate instructional design to accommodate specific contexts and values.

Table 1.

Key dimensions shaping learning environments and outcomes in CBL and PBL
• Occasion for engaging content: Contextualized (case based) or decontextualized?
• Mode of engaging student: Problem based or authority based?
• Instructional focus: Content, skills, and/or nature of science?
• Epistemic process: Apply knowledge or generate new knowledge?
• Setting: Historical case or contemporary case?
• Epistemic process: Open-ended or close-ended?
• Authenticity: Real case or constructed case?
• Clarity of problem: Well defined, ill defined, or unspecified?
• Social epistemic dimension: Collaborative or individual?
• Complexity of social epistemics: Single perspective or multiple perspectives?
• Scope: Narrow or broad?
• Level of student autonomy: Narrow or broad?
Open in a separate windowFocusing on distinctions in pedagogical approaches encourages one to think more rigorously about educational values and aims. For example, is knowing content the ultimate aim? To what degree is understanding scientific practice and/or its cultural contexts also important? What are the aims regarding analytical or problem-solving skills—or learning how to learn beyond the classroom? Is student motivation, or engagement in learning, a goal? Does one hope to shape student attitudes about the value or authority of science—or to recruit more students into scientific careers or to promote greater gender or ethnic balance? What role is afforded to student autonomy, either in shaping one''s own learning trajectory or as an independent thinker? Possible outcomes range from traditional conceptual content to skills, attitudes, and epistemic understanding. Different methods foster different outcomes. The goal here is to help one clarify one''s aims and align them with the appropriate strategies or teaching tools.3  相似文献   

17.
A Web Application for Generation of Random DNA Sequences with a Single Open Reading Frame: Exemplars for Genetics and Bioinformatics Education     
Steven M. Carr  H. Todd Wareham  Donald Craig 《CBE life sciences education》2014,13(3):373-374
A standard genetic/bioinformatic activity in the genomics era is the identification within DNA sequences of an "open reading frame" (ORF) that encodes a polypeptide sequence. As an educational introduction to such a search, we provide a webapp that composes, displays for solution, and then solves short DNA exemplars with a single ORFTo the Editor: We wish to bring a new Web resource to the attention of CBE—Life Sciences Education readers.When being introduced to the central dogma of nucleic acid transactions, students are often required to identify the 5′→3′ DNA template strand in a double-stranded DNA (dsDNA) molecule; transcribe an antiparallel, complementary 5′→3′ mRNA; and then translate the mRNA codons 5′→3′ into an amino acid polypeptide by means of the genetic code table. Although this algorithm replicates the molecular genetic process of protein synthesis, experience shows that the series of left/right, antiparallel, and/or 5′→3′ reversals is confusing to many students when worked by hand. Students may also obtain the “right” answer for the “wrong” reasons, as when the “wrong” DNA strand is transcribed in the “wrong” 3′→5′ direction, so as to produce a string of letters that “translates correctly.”In genetics and bioinformatics education, we have found it more intuitively appealing to demonstrate and emphasize the equivalence of the mRNA to the DNA sense strand complement of the template strand. The sense strand is oriented in the same 5′→3′ direction and has a sequence identical to the mRNA, except for substitution of thymidine in the DNA for uracil in the mRNA. It is thus more computationally efficient to “read” the polypeptide sequence directly from this strand, with mental substitution of thymidine in the triplets of the genetic code table. (By definition, “codons” occur only in mRNA: the equivalent three-letter words in the DNA sense strand may be designated “triplets.”) This is the same logic used in DNA “translation” software programs.A further constraint often imposed on dsDNA teaching exemplars is that five of the six possible reading frames are “closed” by the occurrence of one or more “stop” triplets, and only one is an open reading frame (ORF) that encodes an uninterrupted polypeptide. We designate this the “5&1” condition. The task for the student is to identify the ORF and “translate” it correctly. Other considerations include correct labeling of the sense and template DNA strands, their 5′ and 3′ ends (and of the mRNA as required), and the amino (N) and carboxyl (C) termini of the polypeptide.Thus, instructors face the logistical challenge of creating dsDNA sequences that satisfy the “5&1” condition for homework and exam questions. Instructors must compose sequences with one or more “stops” in the three overlapping read frames of one strand, while simultaneously creating two “stopped” frames and one ORF in the other. We have explored these constraints as an algorithmic and computational challenge (Carr et al., 2014 ). There are no “5&1” exemplars of length L ≤ 10, and the proportion of exemplars of length L ≥ 11 is very small relative to the 4L possible sequences (e.g., 0.0023% for L = 11, 0.048% for L = 15, 0.89% for L = 25). This makes random exploration for such exemplars inefficient.We therefore developed a two-stage recursive search algorithm that samples 4L space randomly to generate “5&1” exemplars of any specified length L from 11 ≤ L ≤ 100. The algorithm has been implemented as a Web application (“RandomORF,” available at www.ucs.mun.ca/~donald/orf/randomorf). Figure 1 shows a screen capture of the successive stages of the presentation. The application requires JavaScript on the computer used to run the Web browser.Open in a separate windowFigure 1.Successive screen captures of the webapp RandomORF. First panel: the Length parameter is the desired number of base pairs. Second panel: Clicking the “Generate dsDNA” button shows the dsDNA sequence to be solved, with labeled 5′ and 3′ ends. The button changes to “Show ORF.” Third panel: A second click shows the six reading frames, with the ORF highlighted. Here, the ORF is in the sixth reading frame on the bottom (sense) strand. The polypeptide sequence, read right to left, is N–EITHLRL–C, where N and C are the amino and carboxyl termini, respectively. The conventional IUPAC single-letter abbreviations for amino acids are centered over the middle base of the triplet; stop triplets are indicated by asterisks (*).The webapp provides a means for students to practice identifying ORFs by efficiently generating many examples with unique solutions (Supplemental Material); this can take the place of the more standard offering of a small number of set examples with an answer key. The two-stage display makes it possible for problems to be worked “cold,” with the correct ORF identified only afterward. For examinations, any exemplar may be presented in any of four ways, by transposing the top and bottom strands and/or reversing the direction of the strands left to right. Presentation of the 5′ end of the sense strand at the lower left or upper or lower right tests student recognition that sense strands are always read in the 5′→3′ direction, irrespective of the “natural” left-to-right and/or top-then-bottom order. We intend to modify the webapp to include other features of pedagogical value, including constraints on [G+C] composition and the type, number, and distribution of stop triplets. We welcome suggestions from readers.  相似文献   

18.
Recent Research in Science Teaching and Learning     
Deborah Allen 《CBE life sciences education》2013,12(3):332-335
This feature is designed to point CBE—Life Sciences Education readers to current articles of interest in life sciences education as well as more general and noteworthy publications in education research.This feature is designed to point CBE—Life Sciences Education readers to current articles of interest in life sciences education as well as more general and noteworthy publications in education research. URLs are provided for the abstracts or full text of articles. For articles listed as “Abstract available,” full text may be accessible at the indicated URL for readers whose institutions subscribe to the corresponding journal.1. Bush SD, Pelaez NJ, Rudd JA, Stevens MT, Tanner KD, Williams KS (2013). Widespread distribution and unexpected variation among science faculty with education specialties (SFES) across the United States. Proc Natl Acad Sci USA 110, 7170–7175.[Available at: www.pnas.org/content/110/18/7170.full.pdf+html?sid=f2823860-1fef-422c-b861-adfe8d82cef5]College and university basic science departments are taking an increasingly active role in innovating and improving science education and are hiring science faculty with education specialties (SFES) to reflect this emphasis. This paper describes a nationwide survey of these faculty at private and public degree-granting institutions. The authors assert that this is the first such analysis undertaken, despite the apparent importance of SFES at many, if not most, higher education institutions. It expands on earlier work summarizing survey results from SFES used in the California state university system (Bush et al., 2011 ).The methods incorporated a nationwide outreach that invited self-identified SFES to complete an anonymous, online survey. SFES are described as those “specifically hired in science departments to specialize in science education beyond typical faculty teaching duties” or “who have transitioned after their initial hire to a role as a faculty member focused on issues in science education beyond typical faculty teaching duties.” Two hundred eighty-nine individuals representing all major types of institutions of higher education completed the 95-question, face-validated instrument. Slightly more than half were female (52.9%), and 95.5% were white. There is extensive supporting information, including the survey instrument, appended to the article.Key findings are multiple. First, but not surprisingly, SFES are a national, widespread, and growing phenomenon. About half were hired since the year 2000 (the survey was completed in 2011). Interestingly, although 72.7% were in tenured or tenure-track positions, most did not have tenure before adopting SFES roles, suggesting that such roles are not, by themselves, an impediment to achieving tenure. A second key finding was that SFES differed significantly more between institutional types than between science disciplines. For example, SFES respondents at PhD-granting institutions were less likely to occupy tenure-track positions than those at MS-granting institutions and primarily undergraduate institutions (PUIs). Also, SFES at PhD institutions reported spending more time on teaching and less on research than their non-SFES peers. This may be influenced, of course, by the probability that fewer faculty at MS and PUI institutions have research as a core responsibility. The pattern is complex, however, because all SFES at all types of institutions listed teaching, service, and research as professional activities. SFES did report that they were much more heavily engaged in service activities than their non-SFES peers across all three types of institutions. A significantly higher proportion of SFES respondents at MS-granting institutions had formal science education training (60.9%), as compared with those at PhD-granting institutions (39.3%) or PUIs (34.8%).A third finding dealt with success of SFES in obtaining funding for science education research, with funding success defined as cumulatively obtaining $100,000 or more in their current positions. Interestingly, the factors that most strongly correlated statistically with funding success were 1) occupying a tenure-track position, 2) employment at a PhD-granting institution, and 3) having also obtained funding for basic science research. Not correlated were disciplinary field and, surprisingly, formal science education training.Noting that MS-granting institutions show the highest proportions of SFES who are tenured or tenure-track, who are higher ranked, who are trained in science education, and who have professional expectations aligned with those of their non-SFES peers, the authors suggest that these institutions are in the vanguard of developing science education as an independent discipline, similar to ecology or organic chemistry. They also point out that SFES at PhD institutions appear to be a different subset, occupying primarily non–tenure track, teaching positions. To the extent that more science education research funding is being awarded to these latter SFES, who occupy less enfranchised roles within their departments, the authors suggest the possibility that such funding may not substantially improve science education at these institutions. However, the authors make it clear that the implications of their findings merit more careful examination and discussion.2. Opfer JE, Nehm RH, Ha M (2012). Cognitive foundations for science assessment design: knowing what students know about evolution. J Res Sci Teach 49, 744–777.[Abstract available: http://onlinelibrary.wiley.com/doi/10.1002/tea.21028/abstract]The authors previously published an article (Nehm et al., 2012) documenting a new instrument (more specifically, a short-answer diagnostic test), Assessing Contextual Reasoning about Natural Selection (ACORNS). This article describes how cognitive principles were used in designing the theoretical framework of ACORNS. In particular, the authors attempted to follow up on the premise of a National Research Council (2001) report on educational assessment that use of research-based, cognitive models for student learning could improve the design of items used to measure students’ conceptual understandings.In applying this recommendation to design of the ACORNS, the authors were guided by four principles for assessing the progression from novice to expert in using core concepts of natural selection to explain and discuss the process of evolutionary change. The items in ACORNS are designed to assess whether, in moving toward expertise, individuals 1) use core concepts for facilitation of long-term recall; 2) continue to hold naïve ideas coexistent with more scientifically normative ones; 3) offer explanations centered around mechanistic rather than teleological causes; and 4) can use generalizations (abstract knowledge) to guide reasoning, rather than focusing on specifics or less-relevant surface features. Thus, these items prioritize recall over recognition, detect students’ use of causal features of natural selection, test for coexistence of normative and naïve conceptions, and assess students’ focus on surface features when offering explanations.The paper provides an illustrative set of four sample items, each of which describes an evolutionary change scenario with different surface features (familiar vs. unfamiliar taxa; plants vs. animals) and then prompts respondents to write explanations for how the change occurred. To evaluate the ability of items to detect gradations in expertise, the authors enlisted the participation of 320 students enrolled in an introductory biology sequence. Students’ written explanations for each of the four items were independently coded by two expert scorers for presence of core concepts and cognitive biases (deviations from scientifically normative ideas and causal reasoning). Indices were calculated to determine the frequency, diversity, and coherence of students’ concept usage. The authors also compared the students’ grades in a subsequent evolutionary biology course to determine whether the use of core concepts and cognitive biases in their ACORNS explanations could successfully predict future performance.Evidence from these qualitative and quantitative data analyses argued that the items were consistent with the cognitive model and four guiding principles used in their design, and that the assessment could successfully predict students’ level of academic achievement in subsequent study of evolutionary biology. The authors conclude by offering examples of student explanations to highlight the utility of this cognitive model for designing assessment items that document students’ progress toward expertise.3. Sampson V, Enderle P, Grooms J (2013). Development and initial validation of the Beliefs about Reformed Science Teaching and Learning (BARSTL) questionnaire. School Sci Math 113, 3–15.[Available: http://onlinelibrary.wiley.com/doi/10.1111/j.1949-8594.2013.00175.x/full]The authors report on the development of a Beliefs about Reformed Science Teaching and Learning (BARSTL) instrument (questionnaire), designed to map teachers’ beliefs along a continuum from traditional to reform-minded. The authors define reformed views of science teaching and learning as being those that are consistent with constructivist philosophies. That is, as quoted from Driver et al. (1994 , p. 5), views that stem from the basic assumption that “knowledge is not transmitted directly from one knower to another, but is actively built up by the learner” by adjusting current understandings (and associated rules and mental models) to accommodate and make sense of new information and experiences.The basic premise for the instrument development posed by the authors is that teachers’ beliefs about the nature of science and of the teaching and learning of science serve as a filter for, and thus strongly influence how they enact, reform-based curricula in their classrooms. They cite a study from a high school physics setting (Feldman, 2002 ) to illustrate the impact that teachers’ differing beliefs can have on the ways in which they incorporate the same reform-based curriculum into their courses. They contend that, because educational reform efforts “privilege” constructivist views of teaching and learning, the BARSTL instrument could inform design of teacher education and professional development by monitoring the extent to which the experiences they offer are effective in shifting teachers’ beliefs toward the more constructivist end of the continuum.The BARTSL questionnaire described in the article has four subscales, with eight items per subscale. The four subscales are: a) how people learn about science; b) lesson design and implementation; c) characteristics of teachers and the learning environment; and d) the nature of the science curriculum. In each subscale, four of the items were designed to be aligned with reformed perspectives on science teaching and learning, and four to have a traditional perspective. Respondents indicate the extent to which they agree with the item statements on a 4-point Likert scale. In scoring the responses, strong agreement with a reform-based item is assigned a score of 4 and strong disagreement a score of 1; scores for traditional items were assigned on a reverse scale (e.g., 1 for strong agreement). A more extensive characterization of the subscales is provided in the article, along with all of the instrument items (see Appendix).The article describes the seven-step process and associated analyses used to, in the words of the authors, “assess the degree to which the BARTSL instrument has accurately translated the construct, reformed beliefs about science teaching, into an operationalization.” The steps include: 1) defining the specific constructs (concepts that can be used to explain related phenomena) that the instrument would measure; 2) developing instrument items; 3) evaluating items for clarity and comprehensibility; 4) evaluating construct and content validity of the items and subscales; 5) a first round of evaluation of the instrument; 6) item and instrument revision; and 7) a second evaluation of validity and reliability (the extent to which the instrument yields the same results on repetition). Step 3 was accomplished by science education doctoral students who reviewed the items and provided feedback, and step 4 with assistance from a seven-person panel composed of science education faculty and doctoral students. Administration of the instrument to 104 elementary teacher education majors (ETEs) enrolled in a teaching method course was used to evaluate the first draft of the instrument and identify items for inclusion in the final instrument. The instrument was administered to a separate population of 146 ETEs in step 7.The authors used two estimates of internal consistency, a Spearman-Brown corrected correlation and coefficient alpha, to assess the reliability of the instrument; the resulting values were 0.80 and 0.77, respectively, interpreted as being indicative of satisfactory internal consistency. Content validity, defined by the authors as the degree to which the sample of items measures what the instrument was designed to measure, was assessed by a panel of experts who reviewed the items within each of the four subscales. The experts concluded that items that were designed to be consistent with reformed and traditional perspectives were in fact consistent and were evenly distributed throughout the instrument. To evaluate construct validity (which was defined as the instrument''s “theoretical integrity”), the authors performed a correlation analysis on the four subscales to examine the extent to which each could predict the final overall score on the instrument and thus be viewed as a single construct of reformed beliefs. They found that each of the subscales was a good predictor of overall score. Finally, they performed an exploratory factor analysis and additional follow-up analyses to determine whether the four subscales measure four dimensions of reformed beliefs and to ensure that items were appropriately distributed among the subscales. In general, the authors contend that the results of these analyses indicated good content and construct validity.The authors conclude by pointing out that BARTSL scores could be used for quantitative comparisons of teachers’ beliefs and stances about reform-minded science teaching and learning and for following changes over time. However, they recommend BARTSL scores not be used to infer a given level of reform-mindedness and are best used in combination with other data-collection techniques, such as observations and interviews.4. Meredith DC, Bolker JA (2012). Rounding off the cow: challenges and successes in an interdisciplinary physics course for life sciences students. Am J Phys 80, 913–922.[Abstract available at: http://ajp.aapt.org/resource/1/ajpias/v80/i10/p913_s1?isAuthorized=no]There is a well-recognized need to rethink and reform the way physics is taught to students in the life sciences, to evaluate those efforts, and to communicate the results to the education community. This paper describes a multiyear effort at the University of New Hampshire by faculties in physics and biological sciences to transform an introductory physics course populated mainly by biology students into an explicitly interdisciplinary course designed to meet students’ needs.The context was that of a large-enrollment (250–320 students), two-semester Introductory Physics for Life Science Students (IPLS) course; students attend one of two lecture sections that meet three times per week and one laboratory session per week. The IPLS course was developed and cotaught by the authors, with a goal of having “students understand how and why physics is important to biology at levels from ecology and evolution through organismal form and function, to instrumentation.” The selection of topics was drastically modified from that of a traditional physics course, with some time-honored topics omitted or de-emphasized (e.g., projectile motion, relativity), and others thought to be more relevant to biology introduced or emphasized (e.g., fluids, dynamics). In addition, several themes not always emphasized in a traditional physics course but important in understanding life processes were woven through the IPLS course: scaling, estimation, and gradient-driven flows.It is well recognized that life sciences students need to strengthen their quantitative reasoning skills. To address their students’ needs in this area, the instructors ensured that online tutorials were available to students, mathematical proofs that the students are not expected use were de-emphasized, and Modeling Instruction labs were incorporated that require students to model their own data with an equation and compose a verbal link between their equations and the physical world.Student learning outcomes were assessed through the use of the Colorado Learning Attitudes about Science Survey (CLASS), which measures students’ personal epistemologies of science by their responses on a Likert-scale survey. These data were supplemented by locally developed, open-ended surveys and Likert-scale surveys to gauge students’ appreciation for the role of physics in biology. Students’ conceptual understanding was evaluated using the Force and Motion Concept Evaluation (FCME) and Test of Understanding Graphs in Kinematics (TUG-K), as well as locally developed, open-ended physics problems that probed students’ understanding in the context of biology-relevant applications and whether their understanding of physics was evident in their use of mathematics.The results broadly supported the efficacy of the authors’ approaches in many respects. More than 80% of the students very strongly or strongly agreed with the statement “I found the biological applications interesting,” and almost 60% of the students very strongly or strongly agreed with the statements “I found the biological applications relevant to my other courses and/or my planned career” and “I found the biological applications helped me understand the physics.” Students were also broadly able to integrate physics into their understanding of living systems. Examples of questions that students addressed include one that asked students to evaluate the forces on animals living in water versus those on land. Ninety-one percent of the students were able to describe at least one key difference between motion in air and water. Gains in the TUG-K score averaged 33.5% across the 4 yr of the course offering and were consistent across items. However, the positive attitudes about biology applications in physics were not associated with gains in areas of conceptual understanding measured by the FCME instrument. These gains were more mixed than those from the TUG-K and dependent on the concept being evaluated, with values as low as 15% for some concepts and an average gain on all items of 24%. Overall, the gains on the two instruments designed to measure physics understanding were described by the authors as being “modest at best,” particularly in the case of the FCME, given that reported national averages for reformed courses for this instrument range from 33 to 93%.The authors summarize by identifying considerations they think are essential to design and implementation of a IPLS-like course: 1) the need to streamline the coverage of course topics to emphasize those that are truly aligned with the needs of life sciences majors; 2) the importance of drawing from the research literature for evidence-based strategies to motivate students and aid in their development of problem-solving skills; 3) taking the time to foster collaborations with biologists who will reinforce the physics principles in their teaching of biology courses; and 4) considering the potential constraints and limitations to teaching across disciplinary boundaries and beginning to strategize ways around them and build models for sustainability. The irony of this last recommendation is that the authors report having suspended the teaching of IPLS at their institution due to resource constraints. They recommend that institutions claiming to value interdisciplinary collaboration need to find innovative ways to reward and acknowledge such collaborations, because “external calls for change resonate with our own conviction that we can do better than the traditional introductory course to help life science students learn and appreciate physics.”I invite readers to suggest current themes or articles of interest in life science education, as well as influential papers published in the more distant past or in the broader field of education research, to be featured in Current Insights. Please send any suggestions to Deborah Allen (ude.ledu@nellaed).  相似文献   

19.
Adding to the Biology Education Research Tool Kit: Research Methods Essays     
Erin L. Dolan  Elisa Stone 《CBE life sciences education》2013,12(3):320-321
  相似文献   

20.
Plant Behavior     
Dennis W. C. Liu 《CBE life sciences education》2014,13(3):363-368
Plants are a huge and diverse group of organisms ranging from microscopic marine phytoplankton to enormous terrestrial trees. Stunning, and yet some of us take plants for granted. In this plant issue of LSE, WWW.Life Sciences Education focuses on a botanical topic that most people, even biologists, do not think about—plant behavior.Plants are a huge and diverse group of organisms (Figure 1), ranging from microscopic marine phytoplankton (see http://oceandatacenter.ucsc.edu/PhytoGallery/phytolist.html for beautiful images of many species) to enormous terrestrial trees epitomized by the giant sequoia: 300 feet tall, living 3000 years, and weighing as much as 3000 tons (visit the Arkive website, www.arkive.org/giant-sequoia/sequoiadendron-giganteum, for photos and basic information). Stunning, and yet some of us take plants for granted, like a side salad. We may see plants as a focal point during the blooming season or as a nice backdrop for all the interesting things animals do. For this plant issue of CBE—Life Sciences Education, I am going to focus on a botanical topic that most people, even biologists, do not think about—plant behavior.Open in a separate windowFigure 1.Plants are very diverse, ranging in size from microscopic plankton (left, courtesy of University of California–Santa Cruz Ocean Data Center) to the biggest organisms on our planet (right, courtesy Arkive.org).Before digging into plant behavior, let us define what a plant is. All plants evolved from the eukaryotic cell that acquired a photosynthetic cyanobacterium as an endosymbiont ∼1.6 billion years ago. This event gave the lineage its defining trait of being a eukaryote that can directly harvest sunlight for energy. The cyanobacteria had been photosynthesizing on their own for a long time already, but this new “plant cell” gave rise to a huge and diverse line of unicellular and multicellular species. Genome sequences have shed light on the birth and evolution of plants, and John Bowman and colleagues published an excellent review titled “Green Genes” several years ago in Cell (www.sciencedirect.com/science/article/pii/S0092867407004618#; Bowman et al., 2007 ). The article has concise information on the origin and evolution of plant groups, including helpful graphics (Figure 2). Of course, plants were classified and subdivided long before DNA analysis was possible. The Encyclopedia of Earth (EOE) is a good website for exploring biological diversity and has an article on plants (www.eoearth.org/view/article/155261) that lays out the major plant groups and their characteristics. It states that there are more than 400,000 described species, a fraction of the estimated total number.Open in a separate windowFigure 2.Genomic analysis has illuminated the relationship among the many species of plants, as illustrated in this phylogeny of three major plant groups from Bowman et al. (2007 , p. 129).The venerable Kew Gardens has an excellent website (Figure 3) that includes extensive pages under the tab Science and Conservation (www.kew.org/science-conservation). It is a beautifully organized website for exploring plant diversity and burrowing into the science of plants, and includes an excellent blog. Ever wonder how many different kinds of flowers there are? You can find out by visiting their feature titled, “How Many Flowering Plants Are There in the World?” There is an interesting video feature on coffee, which describes how only two species out of more than a hundred have come to dominate coffee production for drinking. As the monoculture in Ireland led to the potato blight, a lack of genetic diversity in today''s coffee plants is threatening the world''s coffee supply with the onset of climate change. The possibility of life without coffee is a call to action if ever I have heard one.Open in a separate windowFigure 3.Kew Gardens has a large and informative website that should appeal to gardeners and flower lovers, as well as more serious botanists and ecologists.Classification of plants is challenging for students and teachers alike. Perhaps understandable, given that plants constitute an entire kingdom of life. For an overview, have students read the EOE article as well as the Bowman Cell article to appreciate the enormity and diversity of the organisms we call plants. The EOE article is reproduced on the Encyclopedia of Life website (http://eol.org/info/449), an excellent context for further exploration of diverse plant species. As we probe the topic of plant behavior, the examples will be drawn from the vascular plants that include the many familiar plants commonly called trees, shrubs, flowers, vegetables, and weeds.Plants do respond to changes in their environment, but is it fruitful or scientifically valid to say that they have behavior? They lack muscles and nerves, do not have mouths or digestive systems, and are often literally rooted in place. A growing number of plant biologists have embraced the term behavior, as demonstrated by the journal devoted to the subject, Plant Behavior. Their resources page (www.plantbehavior.org/resources.html) is a good place to get oriented to the field.As in so many things, Darwin anticipated important questions concerning the movement of plants, despite the difficulties in observing plant behavior, and in 1880 he published The Power of Movement in Plants. The Darwin Correspondence Project website has a good treatment of Darwin''s work on plants, with interesting anecdotes relating to how he collaborated with his son Francis on this work late in his career (www.darwinproject.ac.uk/power-of-movement-in-plants). You can download Chapter 9 of the book and some of the correspondence between Darwin and his son. The entire book is available at http://darwin-online.org.uk/content/frameset?itemID=F1325&viewtype=text&pageseq=1, or in various e-reader formats at the Project Gutenberg website (http://www.gutenberg.org/ebooks/5605). The PBS NOVA website, has a feature covering several of Darwin''s “predictions,” including one in which he noted the importance of plant and animal interactions. He famously predicted that a Madagascar orchid (Angraecum sesquipedale), which has a long narrow passage to its nectar stash, must have a long-tongued pollinator. In 1903, biologists identified the giant hawkmoth, with a 12-inch-long proboscis, as the pollinator predicted by Darwin (www.pbs.org/wgbh/nova/id/pred-nf.html).Darwin recognized that plants mostly do things on a timescale that is hard for us to observe, so he devised clever ways to record their movements. Placing a plant behind a pane of glass, he marked the plant''s position on the glass over time using a stationary reference grid placed behind the plant. Darwin transferred the drawing to a sheet of paper before cleaning the glass for the next experiment (Figure 4). By varying the distance between the plant, the reference points, and the glass, he magnified apparent distances to detect even small plant movements over periods as short as minutes. High-definition time-lapse photography and other modern techniques have extended Darwin''s observations in some compelling directions.Open in a separate windowFigure 4.One of Darwin''s drawings that can be found on the Darwin Correspondence Project Web pages devoted to his book The Power of Movement in Plants. For this figure, the position of the cotyledons of a Brassica was marked on a glass plate about every 30 min over a period of more than 10 h.A recent episode of the PBS Nature series, “What Plants Talk About,” epitomizes the increased interest in plant behavior and, unfortunately, some of the hyperbole associated with the field. The time-lapse video sequences and associated science are fascinating, and the entire program can be viewed on the PBS website at http://video.pbs.org/video/2338524490. The home page for the program (Figure 5; www.pbs.org/wnet/nature/episodes/what-plants-talk-about/introduction/8228) has two short video clips that are interesting. The video titled “Dodder Vine Sniffs Out Its Prey” is nicely filmed and features some interesting experiments involving plant signaling. It might be instructive to ask students to respond to the vocabulary used in the narration, which unfortunately tries to impart intent and mindfulness to the plant''s activities, and to make sensible experimental results somehow seem shocking. The “Plant Self-Defense” video is a compelling “poison pill” story that needs no narrative embellishment. A plant responds to caterpillars feeding on it by producing a substance that tags them for increased attention from predators. Increased predation reduces the number of caterpillars feeding on the plants. The story offers a remarkable series of complex interactions and evolutionary adaptations. Another documentary, In the Mind of Plants (www.youtube.com/watch?v=HU859ziUoPc), was originally produced in French. Perhaps some experimental interpretations were mangled in translation, but the camera work is consistently excellent.Open in a separate windowFigure 5.The Nature pages of the PBS website have video clips and a short article, as well as the entire hour-long program “What Plants Talk About.” The program features fantastic camera work and solid science, but some questionable narration.Skepticism is part and parcel of scientific thinking, but particular caution may be warranted in the field of plant behavior because of the 1970s book and documentary called The Secret Life of Plants (www.youtube.com/watch?v=sGl4btrsiHk). The Secret Life of Plants was a sensation at the time and was largely responsible for the persistent myths that talking to your plants makes them healthier, that plants have auras, and that plants grow better when played classical music rather than rock. While the program woke people up to the notion that plants indeed do fascinating things, the conclusions based on bad science or no science at all were in the end more destructive than helpful to this aspect of plant science. Michael Pollan, author of The Botany of Desire and other excellent plant books, addresses some of the controversy that dogs the field of plant behavior in an interview on the public radio program Science Friday (http://sciencefriday.com/segment/01/03/2014/can-plants-think.html). His article “The Intelligent Plant” in the New Yorker (www.newyorker.com/reporting/2013/12/23/131223fa_fact_pollan?currentPage=all), covers similar ground.The excellently understated Plants in Motion website (http://plantsinmotion.bio.indiana.edu/plantmotion) is a welcome antidote to some of the filmic excesses. The site features dozens of low-definition, time-lapse videos of plants moving, accompanied by straightforward explanations of the experimental conditions and some background on the plants. The lack of narration conveys a refreshing cinema verité quality, and you can choose your own music to play while you watch. Highlights include corn shoots growing toward a light bulb, the rapid response of a mimosa plant to a flame, vines twining, and pumpkins plumping at night. You may have driven past a field of sunflowers and heard the remark that the heads follow the sun, but that is a partial truth. The young buds of the early plants do track the sun, but once they bloom, the tall plants stiffen and every head in the field permanently faces … east! The creators of Plants in Motion curated an exhibit at the Chicago Botanic Gardens called sLowlife (Figure 6). The accompanying video and “essay” (http://plantsinmotion.bio.indiana.edu/usbg/toc.htm) are excellent, featuring many interesting aspects of plant biology.Open in a separate windowFigure 6.sLowlife is an evocative multimedia essay designed to accompany an exhibit installed at the Chicago Botanic Gardens. It features text and video that reveal interesting aspects of plant biology.High-definition time-lapse photography is far from the only tool available to reveal hard-to-observe activities of plants. Greg Asner and colleagues at the Carnegie Airborne Observatory are using informatics to study the dynamic lives of plants at the community ecology level. The Airborne Observatory uses several impressive computer- and laser-enabled techniques (http://cao.stanford.edu/?page=cao_systems) to scan the landscape at the resolution of single leaves on trees and in modalities that can yield information at the molecular level. These techniques can yield insights into how forests respond to heat or water stress or the introduction of a new species. The site has a gallery of projects that are best started at this page: http://cao.stanford.edu/?page=research&pag=5. Here, they are documenting the effect of the Amazon megadrought on the rain forest. The very simple navigation at the top right consists of 15 numbered squares for the different projects. Each project is worth paging through to understand how versatile these aerial-mapping techniques are. They also have six buttons of video pages (http://cao.stanford.edu/?page=videos) that give you a feel for what it might be like to be in the air while collecting the data (Figure 7).Open in a separate windowFigure 7.The Carnegie Airborne Observatory is a flying lab that can collect real-time aerial data on forests at resolutions smaller than a single leaf on a tree.If this Feature seems to have been too conservative about whether plants have behavior, visit the LINV blog (www.linv.org/blog/category/plant-behavior) of the International Laboratory for Plant Neurobiology. The term “plant neurobiology” may be going too far, but the website presents some interesting science. Another fascinating dimension of plant “behavior” is seed dispersal, from seeds that can burrow, to seeds that “fly,” to seeds that are shot like bullets. A couple of websites have some good information and photos of the myriad designs that have evolved to take advantage of air currents for seed dispersal; see http://waynesword.palomar.edu/plfeb99.htm and http://theseedsite.co.uk/sdwind.html. The previously mentioned PBS Nature series also produced a program on seeds, “The Seedy Side of Plants,” which you can view at www.pbs.org/wnet/nature/episodes/the-seedy-side-of-plants/introduction/1268. ChloroFilms, a worldwide competition for plant videos, is now in its fourth season, with some really good videos (www.chlorofilms.org). If you love plants, work with plants, or have insights into plant biology, you should consider submitting a video!  相似文献   

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