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1.

This study concerns students’ ideas about the superposition of electric fields. Two paper‐and‐pencil questionnaires were given to university students to investigate possible obstacles to a correct use of this principle.

The results confirm an expected difficulty about Gauss's theorem, i.e., the idea that only ‘internal’ charges create a field on a given closed surface. Another more surprising finding is that students are reluctant to admit that a field can penetrate into, or go out of, an insulator, particularly because ‘charges cannot move’.

These first findings are discussed in connection with common features of students’ reasoning about mechanics and about multivariable problems. Some directions of future research are proposed.  相似文献   

2.

In the last twenty years, researchers have studied students’ mathematical and scientific conceptions and reasoning. Most of this research is content‐specific. It has been found that students often hold ideas that are not in line with accepted scientific notions. In our joint work in mathematics and science education, it became apparent that many of these alternative conceptions hail from a small number of intuitive rules. We have so far identified two such rules: ‘The more of A, the more of B’, and, ‘Everything can be divided by two’. The first rule is reflected in students’ responses to many tasks, including all classical Piagetian conservation tasks (conservation of number, area, weight, volume, matter, etc.), all tasks related to intensive quantities (density, temperature, concentration, etc.), and tasks related to infinite quantities. The second rule is observed in responses related to successive division of material and geometrical objects, and in seriation tasks. In this paper we describe and discuss the second rule and its relevance to science and mathematics education. In a previous paper (Stavy and Tirosh 1995, in press) we described and discussed the first rule.  相似文献   

3.
Summaries

English

The report describes a study of the teaching behaviour of student‐teachers of science disciplines during the one‐term teaching practice of the English ‘Post‐Graduate Certificate in Education’ course, using the Science Teaching Observation Schedule by Eggleston et al.

The results suggest that in several behavioural dimensions, students and teachers achieve a close match. These dimensions, it is suggested, could represent the ‘stable’ elements in the students’ perception of science teacher behaviour learnt during their time as pupils, or they might represent ‘safe’ transactions which do not involve students extensively in problems of classroom management and control.

For other behaviour categories, it was found that students tended to behave less like experienced teachers as the training practice proceeded, but this was to some extent determined by the subject taught. Physics student‐teachers substantially maintained their similarity to experienced teachers, whilst chemistry and biology students drifted away. The nature of these drifts is discussed.  相似文献   

4.
5.
ABSTRACT

Context-based learning (CBL) is advocated as beneficial to learners, but more needs to be understood about how different contexts used in courses influence student outcomes. Gilbert defined several models of context that appear to be used in chemistry. In one model that achieves many criteria of student meaning-making, the context is provided by ‘personal mental activity’, meaning that students engage in a role to solve a problem. The model’s predicted outcomes are that students develop and use the specialised language of chemistry, translate what they learn in the immediate context to other contexts, and empathise with the community of practice that is created. The first two of these outcomes were investigated in two large-enrolment university chemistry courses, both organised as this CBL model, in which students were introduced to kinetic molecular theory (KMT). Sample 1 students (N1?=?105) learned KMT through whole-class kinaesthetic activity as a human model of a gas while focusing on a problem identifying substances in balloons filled with different gases. Sample 2 students (N2?=?110) manipulated molecular dynamics simulations while focusing on the problem of reducing atmospheric CO2. Exam answers and pre-/post-test responses, involving a new KMT context, were analysed. Students in Sample 1 demonstrated a stronger understanding of particle trajectories, while Sample 2 students developed more sophisticated mechanistic reasoning and greater fluidity of translation between contexts through increased use of chemists’ specialised language. The relationships of these outcomes to the contexts were examined in consideration of the different curriculum emphases inherent in the contexts.  相似文献   

6.
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   

7.
This paper highlights specific aspects of high‐school students’ reasoning while coping with a modeling task of plant growth in a computer‐supported educational environment. It is particularly concerned with the modeling levels (‘macro‐phenomenological’ and ‘micro‐conceptual’ level) activated by peers while exploring plant growth and with their ability to shift between or within these levels. The focus is on the types of reasoning developed in the modeling process, as well as on the reasoning coherence around the central concept of plant growth. The findings of the study show that a significant proportion of the 18 participating dyads perform modeling on both levels, while their ability to shift between them as well as between the various elements of the ‘micro‐conceptual’ level is rather constrained. Furthermore, the reasoning types identified in peers’ modeling process are ‘convergent’, ‘serial’, ‘linked’ and ‘convergent attached’, with the first type being the most frequent. Finally, a significant part of the participating dyads display a satisfactory degree of reasoning ‘coherence’, performing their task committed to the main objective of exploring plant growth. Teaching implications of the findings are also discussed.  相似文献   

8.
Researchers have shown a growing interest in science teachers’ professional knowledge in recent decades. The article focuses on how chemistry teachers impart chemical bonding, one of the most important topics covered in upper secondary school chemistry courses. Chemical bonding is primarily taught using models, which are key for understanding science. However, many studies have determined that the use of models in science education can contribute to students’ difficulties understanding the topic, and that students generally find chemical bonding a challenging topic. The aim of this study is to investigate teachers’ knowledge of teaching chemical bonding. The study focuses on three essential components of pedagogical content knowledge (PCK): (1) the students’ understanding, (2) representations, and (3) instructional strategies. We analyzed lesson plans about chemical bonding generated by 10 chemistry teachers with whom we also conducted semi-structured interviews about their teaching. Our results revealed that the teachers were generally unaware of how the representations of models they used affected student comprehension. The teachers had trouble specifying students’ difficulties in understanding. Moreover, most of the instructional strategies described were generic and insufficient for promoting student understanding. Additionally, the teachers’ rationale for choosing a specific representation or activity was seldom directed at addressing students’ understanding. Our results indicate that both PCK components require improvement, and suggest that the two components should be connected. Implications for the professional development of pre-service and in-service teachers are discussed.  相似文献   

9.
ABSTRACT

Many science curricula and standards emphasise that students should learn both scientific knowledge and the skills associated with the construction of this knowledge. One way to achieve this goal is to use inquiry-learning activities that embed the use of science process skills. We investigated the influence of scientific reasoning skills (i.e. conceptual and procedural knowledge of the control-of-variables strategy) on students’ conceptual learning gains in physics during an inquiry-learning activity. Eighth graders (n?=?189) answered research questions about variables that influence the force of electromagnets and the brightness of light bulbs by designing, running, and interpreting experiments. We measured knowledge of electricity and electromagnets, scientific reasoning skills, and cognitive skills (analogical reasoning and reading ability). Using structural equation modelling we found no direct effects of cognitive skills on students’ content knowledge learning gains; however, there were direct effects of scientific reasoning skills on content knowledge learning gains. Our results show that cognitive skills are not sufficient; students require specific scientific reasoning skills to learn science content from inquiry activities. Furthermore, our findings illustrate that what students learn during guided inquiry activities becomes visible when we examine both the skills used during inquiry learning and the process of knowledge construction. The implications of these findings for science teaching and research are discussed.  相似文献   

10.
Abstract

In order to explore the relationship between moral reasoning and conduct, 38 Grade Six students, deemed by their teachers to display ‘delinquent’ or ‘non‐delinquent’ characteristics, were administered Kohlberg's Moral Judgment Instrument (Kohlberg et al., 1973) and an IQ test. Subjects were then randomly assigned to three treatment groups: a) experimental‐‐discussion of moral dilemmas; b) placebo‐‐social studies games; c) control. A month later Kohlberg's instrument was readministered.

Findings indicated that ‘delinquents’ and ‘non‐delinquents’ differed significantly (p = .001) on moral reasoning scores at both testing times. There was no statistically significant treatment effect (p = .06). Intelligence quotient was significantly and positively related to moral reasoning for ‘non‐delinquents’, but not for ‘delinquents’.  相似文献   

11.
The present paper discusses the conceptual demands of an apparently straightforward task set to secondary‐level students—completing chemical word equations with a single omitted term. Chemical equations are of considerable importance in chemistry, and school students are expected to learn to be able to write and interpret them. However, it is recognised that many students find them challenging. The present paper explores students’ accounts of their attempts to identify the missing terms, to illuminate why working with chemical word equations is so challenging from the learner’s perspective. Three hundred secondary‐age students responded to a five‐item exercise based on chemicals and types of reactions commonly met at school level. For each item they were asked to identify the missing term in a word equation, and to explain their answers. This provided a database containing more than 1,000 student accounts of their rationales. Analysis of the data led to the identification of seven main classes of strategy used to answer the questions. Most approaches required the coordination of chemical knowledge at several different levels for a successful outcome; and there was much evidence both for correct answers based on flawed chemical thinking, and appropriate chemical thinking being insufficient to lead to the correct answer. It is suggested that the model reported here should be tested by more in‐depth methods, but could help chemistry teachers appreciate learners’ difficulties and offer them explicit support in selection and application of strategies when working with chemical equations.  相似文献   

12.
Summaries

English

An outline is given of a programme in applied chemistry within a classical chemistry department of a university located in a Third World country with certain specific needs. The curriculum has been specifically designed to provide students with the knowledge and skills used by chemists in Jamaican industry. Industry personnel were invited to participate fully in the development of the curriculum as well as in actual instruction. In this way, an attempt was made to bridge the gap between the ‘academic’ and the ‘real’ world.

The Third World has experienced a perennial shortage of skilled professional scientists, including chemical engineers. The role of the applied chemist, as envisaged by the authors, has assumed greater importance in the light of this shortage. The programme outlined can probably serve as a basis for discussion in other developing countries contemplating similar programmes.  相似文献   

13.
Concerns regarding students’ learning and reasoning in chemistry classrooms are well documented. Students’ reasoning in chemistry should be characterized by conscious consideration of chemical phenomenon from laboratory work at macroscopic, molecular/sub-micro and symbolic levels. Further, students should develop metacognition in relation to such ways of reasoning about chemistry phenomena. Classroom change eliciting metacognitive experiences and metacognitive reflection is necessary to shift entrenched views of teaching and learning in students. In this study, Activity Theory is used as the framework for interpreting changes to the rules/customs and tools of the activity systems of two different classes of students taught by the same teacher, Frances, who was teaching chemical equilibrium to those classes in consecutive years. An interpretive methodology involving multiple data sources was employed. Frances explicitly changed her pedagogy in the second year to direct students attention to increasingly consider chemical phenomena at the molecular/sub-micro level. Additionally, she asked students not to use the textbook until toward the end of the equilibrium unit and sought to engage them in using their prior knowledge of chemistry to understand their observations from experiments. Frances’ changed pedagogy elicited metacognitive experiences and reflection in students and challenged them to reconsider their metacognitive beliefs about learning chemistry and how it might be achieved. While teacher change is essential for science education reform, students are not passive players in change efforts and they need to be convinced of the viability of teacher pedagogical change in the context of their goals, intentions, and beliefs.  相似文献   

14.
ABSTRACT

Context-based learning aims to make learning more meaningful by raising meaningful problems. However, these types of problems often require reflection and thinking processes that are more complex and thus more difficult for students, putting high demands on students’ problem-solving capabilities. In this paper, students’ approaches when solving context-based chemistry problems and effects of systematic scaffolds are analysed based on the Model of Hierarchical Complexity. Most answers were initially assigned to the lowest level of the model; higher levels were reached without scaffolds only by few students and by most students with scaffolds. The results are discussed with regard to practical implications in terms of how teachers could make use of context-based tasks and aligned scaffolds to help students in this activity.  相似文献   

15.
This article concerns a lacuna in chemistry students' reasoning about chemical bonding. Although chemistry students are familiar with the charges that make up the atom––both positive and negative––they refer only to the attraction between unlike charges. Specifically, they ignore the repulsion between the positive nuclei. We named this disregard of repulsion the lacuna of repulsion. Repulsion is a crucial component in the force-based explanation of chemical bonding, presenting the bond as a dynamic equilibrium between attraction and repulsion electrical forces. We noticed this lacuna incidentally while interviewing chemistry students for a bigger project aimed at supporting students in understanding the force-based explanation of chemical bonding. This article describes our systematic qualitative study of the lacuna of repulsion and its impact on mental models of 23 high school chemistry students. Our findings show that students use six mental models, most of them built upon each other. Beginning from a simple mental model that describes the chemical bond as electrons, continuing with the including attraction forces, and completing with repulsion and a dynamic view of the bond. Only when one considers both attraction and repulsion forces and understands the dynamic balance between them is it possible to build the force-based dynamic mental model of chemical bonding.  相似文献   

16.
Background: There has been an increasing emphasis on empowering pre-service and in-service science teachers to attend student reasoning and use formative assessments to guide student learning in recent years. Purpose: The purpose of this study was to explore pre-service science teachers’ pedagogical capacity for formative assessment. Sample: This study took place in Turkey. The participants include 53 pre-service science teachers in their final year of schooling. All but two of the participants are female. Design and methods: We used a mixed-methods methodology in pursing this inquiry. Participants analyzed 28 responses to seven two-tiered questions given by four students of different ability levels. We explored their ability to identify the strengths and weaknesses in students’ answers. We paid particular attention to the things that the pre-service science teachers noticed in students’ explanations, the types of inferences they made about students’ conceptual understanding, and the affordances of pedagogical decisions they made. Results: The results show that the majority of participants made an evaluative judgment (i.e. the answer is correct or incorrect) in their analyses of students’ answers. Similarly, the majority of the participants recognized the type of mistake that the students made. However, they failed to successfully elaborate on fallacies, limitations, or strengths in student reasoning. We also asked the participants to make pedagogical decisions related to what needs to be done next in order to help the students to achieve academic objectives. Results show that 8% of the recommended instructional strategies were of no affordance, 64% of low-affordance, and 28% were of high affordance in terms of helping students achieve the academic objectives. Conclusion: If our goal is to improve pre-service science teachers’ noticing skills, and the affordance of feedback that they provide, engaging them in activities that asks them to attend to students’ ideas and reasoning may be useful.  相似文献   

17.

In the last twenty years researchers have studied students’ mathematical and scientific conceptions and reasoning. Most of this research is content‐specific. It has been found that students often hold ideas that are not in line with accepted scientific notions. In our joint work in mathematics and science education it became apparent that many of these alternative conceptions hail from the same intuitive rules. We have so far identified two such rules: ‘The more of A, the more of B’ and, ‘Everything can be divided by two’. The first rule is reflected in students’ responses to many tasks, including all classical Piagetian conservation tasks (conservation of number, area, weight, volume, matter, etc.), in all tasks related to intensive quantities (density, temperature, concentration, etc.), and in tasks related to infinite quantities. The second rule is observed in responses related to successive division of material and geometrical objects, and in successive dilution tasks. In this paper we describe and discuss the first rule and its relevance to science and mathematics education. In a second paper (Tirosh and Stavy, in press) we shall describe and discuss the second rule.  相似文献   

18.
The characterization of students’ reasoning strategies is of central importance in the development of instructional strategies that foster meaningful learning. In particular, the identification of shortcut reasoning procedures (heuristics) used by students to reduce cognitive load can help us devise strategies to facilitate the development of more analytical ways of thinking. The central goal of this qualitative study was thus to investigate heuristic reasoning as used by organic chemistry college students, focusing our attention on their ability to predict the relative acid strength of chemical compounds represented using explicit composition and structural features (i.e., structural formulas). Our results indicated that many study participants relied heavily on one or more of the following heuristics to make most of their decisions: reduction, representativeness, and lexicographic. Despite having visual access to reach structural information about the substances included in each ranking task, many students relied on isolated composition features to make their decisions. However, the specific characteristics of the tasks seemed to trigger heuristic reasoning in different ways. Although the use of heuristics allowed students to simplify some components of the ranking tasks and generate correct responses, it often led them astray. Very few study participants predicted the correct trends based on scientifically acceptable arguments. Our results suggest the need for instructional interventions that explicitly develop college chemistry students’ abilities to monitor their thinking and evaluate the effectiveness of analytical versus heuristic reasoning strategies in different contexts.  相似文献   

19.
Submicrorepresentations (SMRs) are a powerful tool for identifying misconceptions of chemical concepts and for generating proper mental models of chemical phenomena in students’ long‐term memory during chemical education. The main purpose of the study was to determine which independent variables (gender, formal reasoning abilities, visualization abilities, and intrinsic motivation for learning chemistry) have the maximum influence on students’ reading and drawing SMRs. A total of 386 secondary school students (aged 16.3 years) participated in the study. The instruments used in the study were: test of Chemical Knowledge, Test of Logical Thinking, two tests of visualization abilities Patterns and Rotations, and questionnaire on Intrinsic Motivation for Learning Science. The results show moderate, but statistically significant correlations between students’ intrinsic motivation, formal reasoning abilities and chemical knowledge at submicroscopic level based on reading and drawing SMRs. Visualization abilities are not statistically significantly correlated with students’ success on items that comprise reading or drawing SMRs. It can be also concluded that there is a statistically significant difference between male and female students in solving problems that include reading or drawing SMRs. Based on these statistical results and content analysis of the sample problems, several educational strategies can be implemented for students to develop adequate mental models of chemical concepts on all three levels of representations.  相似文献   

20.
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