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1.
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   

2.
ABSTRACT

When 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   

3.
How can students be taught to develop explanations for scientific phenomena on their own when their background knowledge is incomplete or poorly organized? Evidence from historical accounts of scientific discovery suggest that self-generated analogies—analogies produced by the learners themselves—are a tool by which individuals can generate, evaluate, and modify their own explanations. The central research questions for this study were: Can students use a series of self-generated analogies to bring about change in their understanding of a given scientific phenomenon, and what is the nature of the change in understanding? Participants were asked to create, apply, and modify their own analogies—as opposed to applying a specific analogy provided by an outsider—as a heuristic for constructing, evaluating, and modifying their own explanations for a given scientific phenomena. Nontrivial changes in explanation facilitated by the use of generative analogies were observed. Changes in understanding ranged from the emergence of new explanations to the raising of important questions about the nature of the phenomenon.  相似文献   

4.
The present study examined the role of conflict topics and individual differences in epistemic perspectives (absolutism, multiplism, and evaluativism) in students' explanations of expert conflicts. University students (N = 184) completed an epistemic thinking assessment and a conflict explanation assessment regarding two controversies in biology and history. Additionally, thirty students were interviewed and provided detailed conflict explanations that were used to interpret and extend the quantitative results. In the biology problem, conflicts were predominantly attributed to topic complexity and to research methods. In the history problem, conflicts were also predominantly attributed to topic complexity, but also to researchers' personal backgrounds and motivations. Epistemic perspectives were related to specific conflict explanations, suggesting that these perspectives have a role beyond topic differences. Thus, both conflict topics and epistemic perspectives shape lay explanations of experts' conflicts. The findings highlight differences in students’ interpretations of the roles experts play in knowledge construction.  相似文献   

5.
Beginning with a distinction among families of explanations (common, disciplinary, self-, and instructional), this article describes research on two aspects of instructional explanations in history with the aim of contributing to research on explanations and on instructional discourse. The two aspects are: the different epistemic occasions that prompt an explanation and a model of goals and actions for instructional explanations in history. The occasions include events, themes, structures, and metasystems. The four goal states are: understanding the nature of the problem or query under discussion; completing in a coherent way the multiple verbal strands that comprise the explanation; using appropriate, accessible representations and analogies; and identifying fundamental disciplinary principles as they are used. Excerpts from the classroom discourse of an advanced history course provide two examples of instructional explanations that illustrate both the occasions being explained and the model of explanation.  相似文献   

6.

Analogical reasoning is increasingly recognized as an important instrument for promoting conceptual change in science learning. This study characterized students' and physicians' spontaneous use of analogies in reasoning about concepts related to the mechanical properties of cardiovascular physiology. The analogies were made in response to questions at different levels of abstraction from basic physiology to clinical problems. The results indicate that analogies generated by subjects facilitated explanations in a number of ways. These include creating coherent representations in novel situations, bridging gaps in understanding, and triggering associations which result in modified explanations. Subjects at different levels of expertise used analogies differently. The more expert subjects used analogies to facilitate articulation and communication; that is, to illustrate and expand on their explanations. Novices and advanced medical students used more between‐domain analogies to explain all categories of questions. This is less evident in physicians' responses to pathophysiological and clinical problems. The paper discusses ways in which analogies can be used productively, and identifies factors that can lead to a counter‐productive use of analogies resulting in misconceptions and erroneous explanations.  相似文献   

7.
Explanation and generalization in young children's strategy learning   总被引:2,自引:0,他引:2  
Children often learn new problem-solving strategies by observing examples of other people's problem-solving. When children learn a new strategy through observation and also explain the new strategy to themselves, they generalize the strategy more widely than children who learn a new strategy but do not explain. We tested three hypothesized mechanisms through which explanations might facilitate strategy generalization: more accurate recall of the new strategy's procedures; increased selection of the new strategy over competing strategies; or more effective management of the new strategy's goal structure. Findings supported the third mechanism: Explanations facilitated generalization through the creation of novel goal structures that enabled children to persist in use of the new strategy despite potential interference from competing strategies. The facilitative effect of explanation did vary with children's age and did not vary between explanations children created by themselves versus explanations they learned from the experimenter.  相似文献   

8.
Abstract

This study investigated fourth graders’ self‐generated analogies, that is, own analogies giving self‐explanations — opposed to analogies provided by a teacher — and the effects of their collaborative reasoning and arguing over these analogies on individual understanding of three scientific phenomena concerning air pressure. At the beginning the children were individually asked to give their own explanations, explicitly encouraged to think of something similar which could help them to understand better what they had experienced. Then, divided in small groups they were asked to compare their accounts to collabora‐tively reach a shared explanation of each phenomenon. At the end, the children were again individually asked to give their explanations. The data underwent both a qualitative and quantitative analysis. The first showed that the children, on the basis of their alternative representations of what air could do, produced and used their own analogies as self‐explanations both to learn the new material and communicate their understanding to others. Moreover, the analysis of the collaborative reasoning and arguing developed in small group discussions revealed that through steps of critical opposition and co‐construction, the learners negotiated and renegotiated meanings and ideas to share a new common knowledge based on the recognition of more appropriate analogies supporting more advanced explanations. The quantitative analysis showed that socio‐cognitive interaction in small groups was fruitful as the children significantly progressed on an individual plane in giving their own explanations of each phenomenon as well as in recognizing the similarities between the three phenomena. In addition, the qualitative data showed evidence that the children were able to express metacognitive awareness of their conceptual growth. Finally, educational implications have been drawn.  相似文献   

9.
ABSTRACT

In the biological sciences, very little is known about the mechanisms by which doctoral students acquire the skills they need to become independent scientists. In the postsecondary biology education literature, identification of specific skills and effective methods for helping students to acquire them are limited to undergraduate education. To establish a foundation from which to investigate the developmental trajectory of biologists’ research skills, it is necessary to identify those skills which are integral to doctoral study and distinct from skills acquired earlier in students’ educational pathways. In this context, the current study engages the framework of threshold concepts to identify candidate skills that are both obstacles and significant opportunities for developing proficiency in conducting research. Such threshold concepts are typically characterised as transformative, integrative, irreversible, and challenging. The results from interviews and focus groups with current and former doctoral students in cellular and molecular biology suggest two such threshold concepts relevant to their subfield: the first is an ability to effectively engage primary research literature from the biological sciences in a way that is critical without dismissing the value of its contributions. The second is the ability to conceptualise appropriate control conditions necessary to design and interpret the results of experiments in an efficient and effective manner for research in the biological sciences as a discipline. Implications for prioritising and sequencing graduate training experiences are discussed on the basis of the identified thresholds.  相似文献   

10.
Our study explored the prospects and limitations of using machine-learning software to score introductory biology students’ written explanations of evolutionary change. We investigated three research questions: 1) Do scoring models built using student responses at one university function effectively at another university? 2) How many human-scored student responses are needed to build scoring models suitable for cross-institutional application? 3) What factors limit computer-scoring efficacy, and how can these factors be mitigated? To answer these questions, two biology experts scored a corpus of 2556 short-answer explanations (from biology majors and nonmajors) at two universities for the presence or absence of five key concepts of evolution. Human- and computer-generated scores were compared using kappa agreement statistics. We found that machine-learning software was capable in most cases of accurately evaluating the degree of scientific sophistication in undergraduate majors’ and nonmajors’ written explanations of evolutionary change. In cases in which the software did not perform at the benchmark of “near-perfect” agreement (kappa > 0.80), we located the causes of poor performance and identified a series of strategies for their mitigation. Machine-learning software holds promise as an assessment tool for use in undergraduate biology education, but like most assessment tools, it is also characterized by limitations.  相似文献   

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模型分析方法是生物学的主要研究方法之一:选择变量,提出假说,建立模型并进行检验。通过应用数学模型方法,生物学研究者可以捕捉到复杂现象的部分相关性细节。对于现象背后复杂的因果网络,即便有效的生物模型也不能否证其他说明的可能,即其所给出的说明不具有排他性理由。在方法论上,生物模型分析方法的应用仍呈现经验论的立场。  相似文献   

14.
Computational thinking (CT) is a way of making sense of the natural world and problem solving with computer science concepts and skills. Although CT and science integrations have been called for in the literature, empirical investigations of such integrations are lacking. Prior work in natural selection education indicates students struggle to explain natural selection in different contexts and natural selection misconceptions are common. In this mixed methods study, secondary honors biology students learn natural selection through CT by engaging in the design of unplugged algorithmic explanations. Students learned CT principles and practices and applied them to learn and explain the natural selection process. Algorithmic explanations were used to scaffold transfer of natural selection knowledge across contexts through investigation of three organisms and the creation of generalized natural selection algorithms. Students' pre- and post-unit algorithmic explanations of natural selection were analyzed to answer the following research questions: (a) How do students' conceptions of natural selection change over the course of a CT focused unit? (b) What is the relationship between CT and natural selection in students' algorithmic explanations? (c) What are students' perspectives of learning natural selection with CT? Results indicate students' conceptions of natural selection increased and natural selection misconceptions decreased over the course of the unit. Within their post-unit algorithmic explanations, students used specific CT principles in conjunction with natural selection concepts to explain natural selection, which helped them to learn the details of the natural selection process and correct their natural selection misconceptions. Students indicated the use of CT in unplugged algorithmic explanations in different contexts helped them learn natural selection. This study shows unplugged CT can be used to teach students science content, and it provides an example for further CT and science integrations. Implications for the field are discussed.  相似文献   

15.

Evidence is presented indicating that spontaneously generated analogies can play a significant role in expert problem solving. Since not all analogies are valid, it is important for the subject to have a way to evaluate their validity. In particular, this paper focuses on an evaluation strategy called bridging that has been observed in solutions to both science and mathematics problems. Spontaneous analogies have also been documented in the problem solving of students. The shared natural use of analogies for unfamiliar problems is an expert‐novice similarity.

Some of the strategies observed in experts were incorporated in a teaching technique for dealing with students’ preconceptions in mechanics. Students taught via these units achieved large gain differences over control groups. Thus non‐deductive reasoning strategies used by experts can give us valuable clues concerning instructional strategies for science students. This complements the prior focus in the literature on expert novice differences with a focus on expert novice similarities.  相似文献   

16.
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   

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As China and the United States become the top two carbon emitters in the world, it is crucial for citizens in both countries to construct a sophisticated understanding of energy consumption issues. This interview study examines how U.S. and Chinese students compare in explaining and arguing about two critical energy consumption issues: burning fossil fuels and using electricity. In particular, we focused on using scientific knowledge to explain and argue about these issues. Based on relevant literature and our previous research, we developed a model to guide separate assessment and evaluation of students’ argumentation and explanation. We conducted clinical interviews with 40 biology majors, including 20 U.S. students and 20 Chinese students. This study generated several important findings. First, Chinese students tended to be less consistent across explanations and argumentation, and their levels of argumentation were lower than their levels of explanation. Second, in comparison to their Chinese counterparts, U.S. students provided more scientific arguments but many fewer scientific explanations. Finally, although all participants were college students and had completed at least one introductory level science course before the interviews, some of their explanations and arguments were based on informal ideas rather than matter and energy. We discuss the possible interpretations of these findings and their implications for teaching and learning of scientific explanation and argumentation in both countries.  相似文献   

19.
This essay analyzes and develops recent views about explanation in biology. Philosophers of biology have parted with the received deductive-nomological model of scientific explanation primarily by attempting to capture actual biological theorizing and practice. This includes an endorsement of different kinds of explanation (e.g., mathematical and causal-mechanistic), a joint study of discovery and explanation, and an abandonment of models of theory reduction in favor of accounts of explanatory reduction. Of particular current interest are philosophical accounts of complex explanations that appeal to different levels of organismal organization and use contributions from different biological disciplines. The essay lays out one model that views explanatory integration across different disciplines as being structured by scientific problems. I emphasize the philosophical need to take the explanatory aims pursued by different groups of scientists into account, as explanatory aims determine whether different explanations are competing or complementary and govern the dynamics of scientific practice, including interdisciplinary research. I distinguish different kinds of pluralism that philosophers have endorsed in the context of explanation in biology, and draw several implications for science education, especially the need to teach science as an interdisciplinary and dynamic practice guided by scientific problems and explanatory aims.  相似文献   

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