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1.
Reasoning across ontologically distinct levels: Students' understandings of molecular genetics 总被引：1，自引：0，他引：1
In this article we apply a novel analytical framework to explore students' difficulties in understanding molecular genetics—a domain that is particularly challenging to learn. Our analytical framework posits that reasoning in molecular genetics entails mapping across ontologically distinct levels—an information level containing the genetic information, and a physical level containing hierarchically organized biophysical entities such as proteins, cells, tissues, etc. This mapping requires an understanding of what the genetic information specifies, and how the physical entities in the system mediate the effects of this information. We therefore examined, through interview and written assessments, 10th grade students' understandings of molecular genetics phenomena to uncover the conceptual obstacles involved in reasoning across these ontologically distinct levels. We found that students' described the genetic instructions as containing information about both the structure and function of biological entities across multiple organization levels; a view that is far less constrained than the scientific understandings of the genetic information. In addition, students were often unaware of the different functions of proteins, their relationship to genes, and the role proteins have in mediating the effects of the genetic information. Students' ideas about genes and proteins hindered their ability to reason across the ontologically distinct levels of genetic phenomena, and to provide causal mechanistic explanations of how the genetic information brings about effects of a physical nature. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 938–959, 2007 相似文献
2.
Ann M.L. Cavallo 《科学教学研究杂志》1996,33(6):625-656
The purpose of this study was to explore relationships among school students' (N = 189) meaningful learning orientation, reasoning ability and acquisition of meaningful understandings of genetics topics, and ability to solve genetics problems. This research first obtained measures of students' meaningful learning orientation (meaningful and rote) and reasoning ability (preformal and formal). Students were tested before and after laboratory-based learning cycle genetics instruction using a multiple choice assessment format and an open-ended assessment format (mental model). The assessment instruments were designed to measure students' interrelated understandings of genetics and their ability to solve and interpret problems using Punnett square diagrams. Regression analyses were conducted to examine the predictive influence of meaningful learning orientation, reasoning ability, and the interaction of these variables on students' performance on the different tests. Meaningful learning orientation best predicted students' understanding of genetics interrelationships, whereas reasoning ability best predicted their achievement in solving genetics problems. The interaction of meaningful learning orientation and reasoning ability did not significantly predict students' genetics understanding or problem solving. Meaningful learning orientation best predicted students' performance on all except one of the open-ended test questions. Examination of students' mental model explanations of meiosis, Punnett square diagrams, and relationships between meiosis and the use of Punnett square diagrams revealed unique patterns in students' understandings of these topics. This research provides information for educators on students' acquisition of meaningful understandings of genetics. © 1996 John Wiley & Sons, Inc. 相似文献
3.
Billie Eilam 《科学教学研究杂志》2004,41(10):970-993
This study investigates how 25 junior high school students employed their bodies of knowledge and responded to problem cues while individually performing a science experiment and reasoning about a drops phenomenon. Line‐by‐line content analysis conducted on students' written ad hoc explanations aimed to reveal students' concepts and their relations within their explanations, and to construe students' mental models for the science phenomenon based on level of specification, models' correspondence with scientific claims, macro versus micro view of matter, and type of evidence used. We then inferred four types of knowledge representations for the nature of matter. Findings are discussed in terms of implications for science teaching. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 970–993, 2004 相似文献
4.
Janice D. Gobert 《International Journal of Science Education》2013,35(9):937-977
Forty-seven fifth grade students (40 group-tested and 7 individually interviewed) read a text describing plate tectonics. At four points they drew diagrams of the spatial, causal, and dynamic processes inside the earth. These diagrams along with students' corresponding explanations, think-aloud protocols (for those individually interviewed), and answers to inference questions were analysed in order to characterize students' models of the interior of the earth, and models of its causal and dynamic processes. Types and characteristics of models, and reasoning associated with them are presented. Additionally, data from two exemplary students are presented as case studies. One student has considerable misunderstandings regarding both her understanding of the spatial layout of the interior of the earth and its causal mechanisms. The second student is more typical in terms of his initial models, but makes large gains in revising his understanding about the causal and dynamic processes inside the earth. In both cases, data are used to infer how each student used their diagrams as artefacts for externalizing knowledge, inference making, and model-revision. 相似文献
5.
Chia-Yu Wang 《International Journal of Science Education》2013,35(2):237-271
This study investigated the effects of scaffolds as cognitive prompts and as metacognitive evaluation on seventh-grade students' growth of content knowledge and construction of scientific explanations in five inquiry-based biology activities. Students' scores on multiple-choice pretest and posttest and worksheets for five inquiry-based activities were analyzed. The results show that the students' content knowledge in all conditions significantly increased from the pretest to posttest. Incorporating cognitive prompts with the explanation scaffolds better facilitated knowledge integration and resulted in greater learning gains of content knowledge and better quality evidence and reasoning. The metacognitive evaluation instruction improved all explanation components, especially claims and reasoning. This metacognitive approach also significantly reduced students' over- or underestimation during peer-evaluation by refining their internal standards for the quality of scientific explanations. The ability to accurately evaluate the quality of explanations was strongly associated with better performance on explanation construction. The cognitive prompts and metacognitive evaluation instruction address different aspects of the challenges faced by the students, and show different effects on the enhancement of content knowledge and the quality of scientific explanations. Future directions and suggestions are provided for improving the design of the scaffolds to facilitate the construction of scientific explanations. 相似文献
6.
Helena Črne-Hladnik Aleš Hladnik Branka Javornik Katarina Košmelj Cirila Peklaj 《International Journal of Science Education》2013,35(8):1277-1296
Quantitative and qualitative studies of various aspects of the perception of biotechnology were conducted among 469 Slovenian high school students of average age 17 years. Our research aimed to explore relationships among students' pre-knowledge of molecular and human genetics, and their attitudes to four specific biotechnological applications. These applications—Bt corn, genetically modified (GM) salmon, somatic and germ line gene therapy (GT)—were investigated from the viewpoints of usefulness, moral acceptance and risk perception. In addition, patterns and quality of moral reasoning related to the biotechnological applications from the aspect of moral acceptability were examined. Clear gender differences were found regarding the relationship between our students' pre-knowledge of genetics and their attitudes to biotechnological applications. While females with a better genetics background expressed a higher risk perception in the case of GM salmon, their similarly well-educated male colleagues emphasized the risk associated with the use of germ line GT. With all four biotechnological applications, patterns of both rationalistic—deontological and teleological—and intuitive moral reasoning were identified. Students with poorer genetics pre-knowledge applied an intuitive pattern of moral reasoning more frequently than their peers with better pre-knowledge. A pattern of emotive reasoning was detected only in the case of GM salmon. A relatively low quality of students' moral reasoning, as demonstrated by their brief and small number of supporting justifications (explanations), show that there is a strong need for practising skills of argumentation about socio-scientific issues in Slovenian high schools on a much larger scale. The implications for future research and classroom applications are discussed. 相似文献
7.
Jenaro Guisasola Jose M. Almudi Kristina Zuza 《International Journal of Science Education》2013,35(16):2692-2717
This study examined engineering and physical science students' understanding of the electromagnetic induction (EMI) phenomena. It is assumed that significant knowledge of the EMI theory is a basic prerequisite when students have to think about electromagnetic phenomena. To analyse students' conceptions, we have taken into account the fact that individuals build mental representations to help them understand how a physical system works. Individuals use these representations to explain reality, depending on the context and the contents involved. Therefore, we have designed a questionnaire with an emphasis on explanations and an interview, so as to analyse students' reasoning. We found that most of the students failed to distinguish between macroscopic levels described in terms of fields and microscopic levels described in terms of the actions of fields. It is concluded that although the questionnaire and interviews involved a limited range of phenomena, the identified explanations fall into three main categories that can provide information for curriculum development by identifying the strengths and weaknesses of students' conceptions. 相似文献
8.
This study examined the outcomes of a unit that integrates explicit teaching of general reasoning patterns into the teaching of a specific science content. Specifically, this article examined the teaching of argumentation skills in the context of dilemmas in human genetics. Before instruction only a minority (16.2%) of the students referred to correct, specific biological knowledge in constructing arguments in the context of dilemmas in genetics. Approximately 90% of the students were successful in formulating simple arguments. An assessment that took place following instruction supported the conclusion that integrating explicit teaching of argumentation into the teaching of dilemmas in human genetics enhances performance in both biological knowledge and argumentation. An increase was found in the frequency of students who referred to correct, specific biological knowledge in constructing arguments. Students in the experimental group scored significantly higher than students in the comparison group in a test of genetics knowledge. An increase was also found in the quality of students' argumentation. Students were able to transfer the reasoning abilities taught in the context of genetics to the context of dilemmas taken from everyday life. The effects of metacognitive thinking and of changing students' thinking dispositions by modifying what is considered valuable in the class culture are discussed. © 2002 John Wiley & Sons, Inc. J Res Sci Teach 39: 35–62, 2002 相似文献
9.
The literature provides confounding information with regard to questions about whether students in high school can engage in meaningful argumentation about socio‐scientific issues and whether this process improves their conceptual understanding of science. The purpose of this research was to explore the impact of classroom‐based argumentation on high school students' argumentation skills, informal reasoning, and conceptual understanding of genetics. The research was conducted as a case study in one school with an embedded quasi‐experimental design with two Grade 10 classes (n = 46) forming the argumentation group and two Grade 10 classes (n = 46) forming the comparison group. The teacher of the argumentation group participated in professional learning and explicitly taught argumentation skills to the students in his classes during one, 50‐minute lesson and involved them in whole‐class argumentation about socio‐scientific issues in a further two lessons. Data were generated through a detailed, written pre‐ and post‐instruction student survey. The findings showed that the argumentation group, but not the comparison group, improved significantly in the complexity and quality of their arguments and gave more explanations showing rational informal reasoning. Both groups improved significantly in their genetics understanding, but the improvement of the argumentation group was significantly better than the comparison group. The importance of the findings are that after only a short intervention of three lessons, improvements in the structure and complexity of students' arguments, the degree of rational informal reasoning, and students' conceptual understanding of science can occur. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 952–977, 2010 相似文献
10.
Learning-by-explaining (to fictitious others) has been shown to be an effective instructional method to support students' generative learning. In this study, we investigated differential effects of the modality of explaining (written versus oral) on students' quality of explanations and learning. Forty-eight students worked on a hypertext about combustion engines. Afterwards, they were asked to explain the learning content, either orally or in writing. Findings indicated that providing written explanations was more effective than providing oral explanations in supporting students to organize the content of the explanations. The higher levels of organization yielded higher levels of students' conceptual knowledge. In contrast, generating oral explanations, relative to written explanations, triggered students' elaborative processes to a more pronounced extent, which was more beneficial to attaining transferable knowledge. Thus, we conclude that the modality of explaining plays a critical role in learning-by-explaining inasmuch as different modes differentially support student learning. 相似文献
11.
Although molecular-level details are part of the upper-secondary biology curriculum in most countries, many studies report that students fail to connect molecular knowledge to phenomena at the level of cells, organs and organisms. Recent studies suggest that students lack a framework to reason about complex systems to make this connection. In this paper, we present a framework that could help students to reason back and forth between cells and molecules. It represents both the general type of explanation in molecular biology and the research strategies scientists use to find these explanations. We base this framework on recent work in the philosophy of science that characterizes explanations in molecular biology as mechanistic explanations. Mechanistic explanations describe a phenomenon in terms of the entities involved, the activities displayed and the way these entities and activities are organized. We conclude that to describe cellular phenomena scientists use entities and activities at multiple levels between cells and molecules. In molecular biological research, scientists use heuristics based on these intermediate levels to construct mechanistic explanations. They subdivide a cellular activity into hypothetical lower-level activities (top-down approaches) and they predict and test the organization of macromolecules into functional modules that play a role in higher-level activities (bottom-up approaches). We suggest including molecular mechanistic reasoning in biology education and we identify criteria for designing such education. Education using molecular mechanistic reasoning can build on common intuitive reasoning about mechanisms. The heuristics that scientists use can help students to apply this intuitive notion to the levels in between molecules and cells. 相似文献
12.
Scientific knowledge often appears to contradict many students' religious beliefs. Indeed, the assumptions of science appear contradictory to the metaphysical claims of many religions. This conflict is most evident in discussions of biological evolution. Teachers, in attempts to limit the controversy, often avoid this topic or teach it superficially. Recently, there has been a political effort to teach to the controversy—which some see as a way of introducing religious explanations for biological diversity into science classrooms. Many science educators reject this approach, insisting that teachers limit classroom discussions to science alone. This science only approach leaves the negotiation of alternative knowledge frameworks to students, who are often ill-prepared for such epistemological comparisons. To support students' understanding of science while maintaining their religious commitments, this article explores the utility of emphasizing the boundaries of scientific knowledge and the need to support students in their comparison of contradictory knowledge frameworks. 相似文献
13.
14.
Ravit Golan Duncan Hava Bresler Freidenreich Clark A. Chinn Andrew Bausch 《Research in Science Education》2011,41(2):147-167
Genetics is the cornerstone of modern biology and understanding genetics is a critical aspect of scientific literacy. Research
has shown, however, that many high school graduates lack fundamental understandings in genetics necessary to make informed
decisions or to participate in public debates over emerging technologies in molecular genetics. Currently, much of genetics
instruction occurs at the high school level. However, recent policy reports suggest that we may need to begin introducing
aspects of core concepts in earlier grades and to successively develop students’ understandings of these concepts in subsequent
grades. Given the paucity of research about genetics learning at the middle school level, we know very little about what students
in earlier grades are capable of reasoning about in this domain. In this paper, we discuss a research study aimed at fostering
deeper understandings of molecular genetics at the middle school level. As part of the research we designed a two-week model-based
inquiry unit implemented in two 7th grade classrooms (N = 135). We describe our instructional design and report results based on analysis of pre/post assessments and written artifacts
of the unit. Our findings suggest that middle school students can develop: (a) a view of genes as productive instructions
for proteins, (b) an understanding of the role of proteins in mediating genetic effects, and (c) can use this knowledge to
reason about a novel genetic phenomena. However, there were significant differences in the learning gains in both classrooms
and we provide speculative explanations of what may have caused these differences. 相似文献
15.
In this study, we analyzed the quality of students' written scientific explanations found in notebooks and explored the link between the quality of the explanations and students' learning. We propose an approach to systematically analyzing and scoring the quality of students' explanations based on three components: claim, evidence to support it, and a reasoning that justifies the link between the claim and the evidence. We collected students' science notebooks from eight science inquiry‐based middle‐school classrooms in five states. All classrooms implemented the same scientific‐inquiry based curriculum. The study focuses on one of the implemented investigations and the students' explanations that resulted from it. Nine students' notebooks were selected within each classroom. Therefore, a total of 72 students' notebooks were analyzed and scored using the proposed approach. Quality of students' explanations was linked with students' performance in different types of assessments administered as the end‐of‐unit test: multiple‐choice test, predict‐observe‐explain, performance assessment, and a short open‐ended question. Results indicated that: (a) Students' written explanations can be reliably scored with the proposed approach. (b) Constructing explanations were not widely implemented in the classrooms studied despite its significance in the context of inquiry‐based science instruction. (c) Overall, a low percentage of students (18%) provided explanations with the three expected components. The majority of the sample (40%) provided only claims without any supporting data or reasoning. And (d) the magnitude of the correlations between students' quality of explanations and their performance, were all positive but varied in magnitude according to the type of assessment. We concluded that engaging students in the construction of high quality explanations may be related to higher levels of student performance. The opportunities to construct explanations in science‐inquiry based classrooms, however, seem to be limited. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 583–608, 2010 相似文献
16.
Elena Bray Speth Neil Shaw Jennifer Momsen Adam Reinagel Paul Le Ranya Taqieddin Tammy Long 《CBE life sciences education》2014,13(3):529-539
Mutation is the key molecular mechanism generating phenotypic variation, which is the basis for evolution. In an introductory biology course, we used a model-based pedagogy that enabled students to integrate their understanding of genetics and evolution within multiple case studies. We used student-generated conceptual models to assess understanding of the origin of variation. By midterm, only a small percentage of students articulated complete and accurate representations of the origin of variation in their models. Targeted feedback was offered through activities requiring students to critically evaluate peers’ models. At semester''s end, a substantial proportion of students significantly improved their representation of how variation arises (though one-third still did not include mutation in their models). Students’ written explanations of the origin of variation were mostly consistent with their models, although less effective than models in conveying mechanistic reasoning. This study contributes evidence that articulating the genetic origin of variation is particularly challenging for learners and may require multiple cycles of instruction, assessment, and feedback. To support meaningful learning of the origin of variation, we advocate instruction that explicitly integrates multiple scales of biological organization, assessment that promotes and reveals mechanistic and causal reasoning, and practice with explanatory models with formative feedback. 相似文献
17.
Anthropogenic climate change remains divisive in the United States, where skepticism of the scientific consensus is associated with conservative worldviews, resulting in political polarization. This study considers three hypotheses regarding U.S. polarization over climate change that have emerged from social psychology research and applies them to science education by showing how these hypotheses could relate to adolescents' science learning. We then test each hypothesis within an experimental educational intervention designed to study the influence of worldview, mechanistic knowledge, and quantitative reasoning on students' written arguments about climate change. We used mixed methods to analyze the results of this individually randomized trial with clustering involving 357 participants in grades 9–11 from 5 U.S. sites. Findings show that: (a) exposure to mechanistic knowledge about climate change increased odds of receptivity toward climate change; (b) increasingly conservative worldviews were associated with decreased odds of receptivity; (c) worldview and quantitative reasoning interacted, resulting in an amplified effect of worldview for students with greater quantitative reasoning. Results also suggest that the influence of worldview and mechanistic knowledge on receptivity work independently from one another in our dataset. This study demonstrates the value of teaching mechanistic understandings of climate change, yet also demonstrates the influence of worldview on receptivity to climate change for adolescents, as well as complex interactions between quantitative reasoning (something school science aims to develop) and worldview. It shows that moving the U.S. public toward the scientific consensus is complex and involves confronting ideologically motivated reasoning within science education. 相似文献
18.
Kathleen Hogan 《科学教学研究杂志》1999,36(10):1085-1109
This study addressed the question of how to increase students' competencies for regulating their co‐construction of knowledge when tackling complex collaborative learning tasks which are increasingly emphasized as a dimension of educational reform. An intervention stressing the metacognitive, regulatory, and strategic aspects of knowledge co‐construction, called Thinking Aloud Together, was embedded within a 12‐week science unit on building mental models of the nature of matter. Four classes of eighth graders received the intervention, and four served as control groups for quantitative analyses. In addition, the interactions of 24 students in eight focal groups were profiled qualitatively, and 12 of those students were interviewed twice. Students who received the intervention gained in metacognitive knowledge about collaborative reasoning and ability to articulate their collaborative reasoning processes in comparison to students in control classrooms, as hypothesized. However, the treatment and control students did not differ either in their abilities to apply their conceptual knowledge or in their on‐line collaborative reasoning behaviors in ways that were attributable to the intervention. Thus, there was a gap between students' metacognitive knowledge about collaborative cognition and their use of collaborative reasoning skills. Several reasons for this result are explored, as are patterns relating students' outcomes to their perspectives on learning science. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 1085–1109, 1999. 相似文献
19.
Cynthia F. Wynne Jim Stewart Cindy Passmore 《International Journal of Science Education》2013,35(5):501-515
Researchers have pointed out the difficulties that high school students have in understanding meiosis and the infrequency with which they acknowledge the conceptual relationships between meiosis and classical genetics, particularly when solving genetics problems. The research described in this article paints a different picture of students' reasoning with meiosis as they solved complex, computergenerated genetics problems, some of which required them to revise their understanding of meiosis in response to anomalous data. Details are presented of the ways students used their knowledge of meiosis to recognize anomalous data, to generate hypotheses as part of the revision of explanatory models, and to assess these hypotheses. The findings from this research, contrary to most reports in the literature, suggest that students are able to develop rich understanding of meiosis and can utilize that knowledge to solve genetics problems. 相似文献
20.
Nilmara Braga Mozzer 《International Journal of Science Education》2013,35(3):429-458
Analogies are parts of human thought. From them, we can acquire new knowledge or change that which already exists in our cognitive structure. In this sense, understanding the analogical reasoning process becomes an essential condition to understand how we learn. Despite the importance of such an understanding, there is no general agreement in cognitive science literature about this issue. In this study, we investigated students' analogical reasoning as a creative process where an environment was set up to foster the students' generating and explaining their own analogies. Data were gathered from pre- and post-teaching interviews, in which the 13–14-year-old students were asked to make comparisons that could explain how atoms are bound. Such data supported the discussion about how students reasoned analogically. Our results made it evident that the task aims and the students' salient knowledge exerted a great influence on the drawing of analogies. 相似文献