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1.
Katelyn M. Southard Melissa R. Espindola Samantha D. Zaepfel 《International Journal of Science Education》2013,35(13):1795-1829
ABSTRACTWhen conducting scientific research, experts in molecular and cellular biology (MCB) use specific reasoning strategies to construct mechanistic explanations for the underlying causal features of molecular phenomena. We explored how undergraduate students applied this scientific practice in MCB. Drawing from studies of explanation building among scientists, we created and applied a theoretical framework to explore the strategies students use to construct explanations for ‘novel’ biological phenomena. Specifically, we explored how students navigated the multi-level nature of complex biological systems using generative mechanistic reasoning. Interviews were conducted with introductory and upper-division biology students at a large public university in the United States. Results of qualitative coding revealed key features of students’ explanation building. Students used modular thinking to consider the functional subdivisions of the system, which they ‘filled in’ to varying degrees with mechanistic elements. They also hypothesised the involvement of mechanistic entities and instantiated abstract schema to adapt their explanations to unfamiliar biological contexts. Finally, we explored the flexible thinking that students used to hypothesise the impact of mutations on multi-leveled biological systems. Results revealed a number of ways that students drew mechanistic connections between molecules, functional modules (sets of molecules with an emergent function), cells, tissues, organisms and populations. 相似文献
2.
Mechanistic reasoning, or reasoning systematically through underlying factors and relationships that give rise to phenomena, is a powerful thinking strategy that allows one to explain and make predictions about phenomena. This article synthesizes and builds on existing frameworks to identify essential characteristics of students’ mechanistic reasoning across scientific content areas. We argue that these characteristics can be represented as epistemic heuristics, or ideas about how to direct one’s intellectual work, that implicitly guide mechanistic reasoning. We use this framework to characterize middle school students’ written explanatory accounts of two phenomena in different science content areas using these heuristics. We demonstrate evidence of heuristics in students’ accounts and show that the use of the heuristics was related to but distinct from science content knowledge. We describe how the heuristics allowed us to characterize and compare the mechanistic sophistication of account construction across science content areas. This framework captures elements of a crosscutting practical epistemology that may support students in directing the construction of mechanistic accounts across content areas over time, and it allows us to characterize that progress. 相似文献
3.
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
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Rayendra Wahyu Bachtiar Ralph F. G. Meulenbroeks Wouter R. van Joolingen 《科学教学研究杂志》2024,61(2):289-318
Previous studies have documented the promising results from student-constructed representations, including stop-motion animation (SMA), in supporting mechanistic reasoning (MR), which is considered an essential thinking skill in science education. Our current study presents theoretically and empirically how student-constructed SMA contributes to promoting MR. As a theoretical perspective, we propose a framework hypothesizing the link between elements of MR and the construction nature of SMA, that is, chunking and sequencing. We then examined the extent to which this framework was consistent with a multiple-case study in the domain of static electricity involving five secondary school students constructing and using their own SMA creation for reasoning. In addition, students' reasoning in pre- and postconstruction of an SMA was examined. Our empirical findings confirmed our framework by showing that all students identified the basic elements of MR, that is, entities and activities of entities, when engaging in chunking and sequencing. Chunking played a role in facilitating students to identify entities responsible for electrostatic phenomena, and sequencing seemed to elicit students to specify activities of these entities. The analysis of students' reasoning in pre- and postconstruction of SMA found that student-generated SMA has a potential effect on students' retention of the use of MR. Implications for instruction with SMA construction to support MR are discussed. 相似文献
6.
Emily E. Scott Jack Cerchiara Jenny L. McFarland Mary Pat Wenderoth Jennifer H. Doherty 《科学教学研究杂志》2023,60(1):63-99
In recent years, there has been a strong push to transform STEM education at K-12 and collegiate levels to help students learn to think like scientists. One aspect of this transformation involves redesigning instruction and curricula around fundamental scientific ideas that serve as conceptual scaffolds students can use to build cohesive knowledge structures. In this study, we investigated how students use mass balance reasoning as a conceptual scaffold to gain a deeper understanding of how matter moves through biological systems. Our aim was to lay the groundwork for a mass balance learning progression in physiology. We drew on a general models framework from biology and a covariational reasoning framework from math education to interpret students' mass balance ideas. We used a constant comparative method to identify students' reasoning patterns from 73 interviews conducted with undergraduate biology students. We helped validate the reasoning patterns identified with >8000 written responses collected from students at multiple institutions. From our analyses, we identified two related progress variables that describe key elements of students' performances: the first describes how students identify and use matter flows in biology phenomena; the second characterizes how students use net rate-of-change to predict how matter accumulates in, or disperses from, a compartment. We also present a case study of how we used our emerging mass balance learning progression to inform instructional practices to support students' mass balance reasoning. Our progress variables describe one way students engage in three dimensional learning by showing how student performances associated with the practice of mathematical thinking reveal their understanding of the core concept of matter flows as governed by the crosscutting concept of matter conservation. Though our work is situated in physiology, it extends previous work in climate change education and is applicable to other scientific fields, such as physics, engineering, and geochemistry. 相似文献
7.
Constructing explanations is an essential skill for all science learners. The goal of this project was to model the key components of expert explanation of molecular and cellular mechanisms. As such, we asked: What is an appropriate model of the components of explanation used by biology experts to explain molecular and cellular mechanisms? Do explanations made by experts from different biology subdisciplines at a university support the validity of this model? Guided by the modeling framework of R. S. Justi and J. K. Gilbert, the validity of an initial model was tested by asking seven biologists to explain a molecular mechanism of their choice. Data were collected from interviews, artifacts, and drawings, and then subjected to thematic analysis. We found that biologists explained the specific activities and organization of entities of the mechanism. In addition, they contextualized explanations according to their biological and social significance; integrated explanations with methods, instruments, and measurements; and used analogies and narrated stories. The derived methods, analogies, context, and how themes informed the development of our final MACH model of mechanistic explanations. Future research will test the potential of the MACH model as a guiding framework for instruction to enhance the quality of student explanations. 相似文献
8.
Relating students' reasoning to the history of science: The case of chemical equilibrium 总被引：1，自引：0，他引：1
In this study, the reasoning of students, who are introduced to the concept of chemical equilibrium, was related to the historical
development of this concept. In the first stage of the study, remarkable similarities were observed between students' reasoning
on the issue of incomplete chemical conversions and the reasoning of 19th-century scientists, especially when molecular notions
were included. In the next stage of the study, some authentic problems and questions, that were essential in the historical
development of chemical equilibrium, were presented to students. It appeared that they recognised the significance of these
problems and questions. Moreover, most students were eager to find explanations. Students, reasoning in molecular terms, would
sometimes explain these problems in terms similar to historical explanations. Other students, however, suggested explanations
in non-molecular terms, which, although chemically valid, did not appear to have historical antecedents. It was concluded
that the study of authentic historical sources may inspire the design of effective teaching activities. 相似文献
9.
Vicente Talanquer 《International Journal of Science Education》2013,35(18):2393-2412
The central goal of our study was to explore the nature of the explanations generated by science and engineering majors with basic training in chemistry to account for the colligative properties of solutions. The work was motivated by our broader interest in the characterisation of the dominant types of explanations that science college students use to make sense of phenomena under conditions of limited time and limited explicit knowledge about a topic. Explanations were collected in written form using two different quizzes that students completed under time constraints at the end of a two‐semester general chemistry course. Our study revealed that students’ ability to generate causal/mechanical explanations depended on the nature of the task. In general, students were more inclined or able to generate mechanistic explanations to account for boiling‐point elevation and freezing‐point depression than to make sense of osmotic flow. The analysis of the types of causal explanations built by the study participants suggests that students may be biased towards some causal models or explanatory modes characterised as causal‐additive and causal‐static in our work. A large proportion of the students built non‐causal teleological explanations to account for osmotic flow. None of the participants in our study used a dynamic model of matter as the basis for their explanations of any of the relevant phenomena; the idea of an underlying random process that is taking place at all times giving rise to emergent properties and behaviours was completely absent from their intuitive reasoning under conditions of limited time and knowledge. 相似文献
10.
Dalit Levy 《Journal of Science Education and Technology》2013,22(5):702-717
This paper reports the results of a study aimed at exploring the advantages of dynamic visualization for the development of better understanding of molecular processes. We designed a technology-enhanced curriculum module in which high school chemistry students conduct virtual experiments with dynamic molecular visualizations of solid, liquid, and gas. They interact with the visualizations and carry out inquiry activities to make and refine connections between observable phenomena and atomic level processes related to phase change. The explanations proposed by 300 pairs of students in response to pre/post-assessment items have been analyzed using a scale for measuring the level of molecular reasoning. Results indicate that from pretest to posttest, students make progress in their level of molecular reasoning and are better able to connect intermolecular forces and phase change in their explanations. The paper presents the results through the lens of improvement patterns and the metaphor of the “ladder of molecular reasoning,” and discusses how this adds to our understanding of the benefits of interacting with dynamic molecular visualizations. 相似文献
11.
Issues regarding scientific explanation have been of interest to philosophers from Pre-Socratic times. The notion of scientific explanation is of interest not only to philosophers, but also to science educators as is clearly evident in the emphasis given to K-12 students' construction of explanations in current national science education reform efforts. Nonetheless, there is a dearth of research on conceptualizing explanation in science education. Using a philosophically guided framework—the Nature of Scientific Explanation (NOSE) framework—the study aims to elucidate and compare college freshmen science students', secondary science teachers', and practicing scientists' scientific explanations and their views of scientific explanations. In particular, this study aims to: (1) analyze students', teachers', and scientists' scientific explanations; (2) explore the nuances about how freshman students, science teachers, and practicing scientists construct explanations; and (3) elucidate the criteria that participants use in analyzing scientific explanations. In two separate interviews, participants first constructed explanations of everyday scientific phenomena and then provided feedback on the explanations constructed by other participants. Major findings showed that, when analyzed using NOSE framework, participant scientists did significantly “better” than teachers and students. Our analysis revealed that scientists, teachers, and students share a lot of similarities in how they construct their explanations in science. However, they differ in some key dimensions. The present study highlighted the need articulated by many researchers in science education to understand additional aspects specific to scientific explanation. The present findings provide an initial analytical framework for examining students' and science teachers' scientific explanations. 相似文献
12.
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
13.
The purpose of this qualitative interpretive research study was to examine high school students’ written scientific explanations
during biology laboratory investigations. Specifically, we characterized the types of epistemologies and forms of reasoning
involved in students’ scientific explanations and students’ perceptions of scientific explanations. Sixteen students from
a rural high school in the Southeastern United States were the participants of this research study. The data consisted of
students’ laboratory reports and individual interviews. The results indicated that students’ explanations were primarily based
on first-hand knowledge gained in the science laboratories and mostly representing procedural recounts. Most students did
not give explanations based on a theory or a principle and did not use deductive reasoning in their explanations. The students
had difficulties explaining phenomena that involved intricate cause–effect relationships. Students perceived scientific explanation
as the final step of a scientific inquiry and as an account of what happened in the inquiry process, and held a constructivist–empiricist
view of scientific explanations. Our results imply the need for more explicit guidance to help students construct better scientific
explanations and explicit teaching of the explanatory genre with particular focus on theoretical and causal explanations. 相似文献
14.
Qualitative changes in intuitive biology 总被引：1，自引：0，他引：1
Recent studies on children’s intuitive biology have indicated that a form of autonomous biology is acquired early in childhood and that later qualitative changes occur within the domain. In this article we focus on two of such changes: (a) In predicting behaviors and attributing properties to an animate object, young children rely on the target’s similarity to people, whereas older children and adults use its category membership and category-behavior (or property) associations; and (b) The modes of explanation change from vitalistic to mechanistic. Whereas young children prefer vitalistic explanations, older children and adults like mechanistic explanations better. We present some experimental findings for these changes. We also indicate how social contexts induce or enhance conceptual change. We discuss three theo-retical issues: implications for conceptual change in biology, for conceptual change in general, and for biology instruction. 相似文献
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Lauren Barth-Cohen 《Instructional Science》2018,46(5):681-705
One line of research on student understanding of complex systems has tended to emphasize discontinuities between common misconceptions and relatively more sophisticated understandings. Other work has focused on instruction while acknowledging the existence of other ways of understanding complex systems, but less emphasis has been on examining the knowledge structures within these intermediate ways of understanding. This study takes a microgenetic approach to examining student’s explanations for the behavior of complex systems. Using the Knowledge-in-Pieces epistemological perspective, the analysis documents a continuity of reasoning patterns across less prototypically centralized and more prototypically decentralized (a more sophisticated causality) explanations while explaining the movement of sand dunes. The first analysis examines 31 interviews and shows that many reflected a general reasoning pattern that encompassing some combination of an initial centralized explanation, a final decentralized explanation, and transitional explanations. A second analysis examines a single student’s reasoning pattern and finds that the activation of relevant intuitive knowledge pieces (p-prims) and transitional explanations function as threads of continuity across the continuum of reasoning patterns. These findings suggest that students are able to exhibit a continuity of reasoning patterns across centralized to decentralized causality and are able to access productive intuitive knowledge about complex systems that are applicable to both the macro and micro levels of sand dune movement. Implications suggest that future research investigate these transitional explanations along with the mechanisms of shifting explanations that can account for this robust continuum. 相似文献
17.
There are two indisputable findings in science education research. First, students go to school with some intuitive beliefs
about the natural world and physical phenomena that pose an obstacle to the learning of formal science. Second, these beliefs
result from the confluence of two factors, namely, their everyday experience as they interact with the world around them and
a set of operational constraints or principles that channel both perceptually and conceptually the way these experiences are
perceived and interpreted. History of science suggests that the theories of early scientists through which they sought to
explain physical phenomena relied mostly on ideas that closely fitted their experiences of the relevant phenomena. This characteristic
of the early scientific ideas is the root of the epistemological difficulties that early scientists faced in their attempts
to explain the phenomena. In this paper, we focus on the early theories in optics (from ancient Greek to the late Islamic
scientific traditions) and argue that students face some of the same epistemological problems as early scientists in explaining
vision and optical phenomena for the reason that students’ intuitive beliefs are also closely tied to particular phenomena
and as a result the underlying notions are fragmentary and lack the necessary generality that would allow them to cover many
disparate phenomena. Knowledge of these epistemological problems can help the instructor to identify the key elements for
a better understanding of the formal theory of optics and, in turn, lead to a more effective instruction. 相似文献
18.
We conducted two studies of beliefs about laboratory and everyday thermal phenomena. The first study identified concepts of heat energy and temperature held by adolescents, adults, and scientists. We found a classic separation of “school” and “everyday” knowledge in each population. We conducted clinical interviews with 37 middle school students, 9 adults, and 8 chemists and physicists to obtain their predictions and explanations of real-world phenomena. Many students believed that metals “conduct,” “absorb,” “trap,” or “hold” cold better than other materials and that aluminum foil would be better than wool or cotton as a wrapping material to keep cold objects cold. Respondents in each group held many intuitive ideas that were well established. Although scientists made more accurate predictions than students and gave theoretical definitions of terms, they too had difficulty explaining everyday phenomena. The second study investigated the impact of a middle school science curriculum designed to help students understand everyday thermal events. We found marked improvements in posttest scores and clinical interview responses as a result of instruction that built on students' intuitions. 相似文献
19.
Explaining natural phenomena is an important goal in science teaching. A logical analysis reveals that causal explanations exhibit formal operational structures in that they consist of implication statements chained together through transitive reasoning. It was hypothesized in the present study that individuals who do not reason formally will have difficulty in learning explanations presented in instruction. To test this hypothesis, the effect of levels of operational thought on the explanations which ninth-grade (n = 26) and college (n = 40) physical science students reconstructed after instruction was investigated. Subjects in the study were classified through Piagetian tests as concrete or formal operational. Both concrete and formal subjects were successful in recalling explanations requiring the chaining of two implication statements. Formal operational subjects performed significantly better than concrete operational subjects in three of the four tests of the reconstruction of complex explanations requiring the chaining of six implication statements. In teaching complex causal explanations to students at the concrete operational level, it is suggested that teachers be prepared to furnish some external structuring which the students can rely on in logically relating the various propositions of the explanation to one another. 相似文献