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1.
This research investigated students' understanding of electrochemistry following a 7–9-week course of instruction. A list of conceptual and propositional knowledge statements was formulated, and this provided the framework for semistructured interviews that were conducted with 32 students in their final year of high school chemistry, following instruction in electrochemistry. Three misconceptions identified in this study and five which have been reported earlier are incorporated into an alternative framework about electric current. The framework is grounded on the notion that a current always involves drifting electrons, even in solution. Another area where students' misconceptions were prevalent was in relation to the sign of the anode and cathode. Students who thought the anode was negatively charged believed cations would move toward it, and those who thought it was positively charged were unable to explain why electrons move away from it. Electrolytic cells also proved troublesome for students. Many students did not associate the positions of the anode and cathode with the polarity of the applied electromotive force (e.m.f.). Other students attempted to reverse features of electrochemical cells and apply the reversals to electrolytic cells. The implications of the research relate to students' interpretation of the language that is used to describe scientific phenomena and the tendency for students to overgeneralize, due to comments made by teachers or statements in textbooks.  相似文献   

2.
This article initially outlines a procedure used to develop a written diagnostic instrument to identify grade-11 and -12 students' misconceptions and misunderstandings of the chemistry topic covalent bonding and structure. The content to be taught was carefully defined through a concept map and propositional statements. Following instruction, student understanding of the topic was identified from interviews, student-drawn concept maps, and free-response questions. These data were used to produce 15 two-tier multiple-choice items where the first tier examined content knowledge and the second examined understanding of that knowledge in six conceptual areas, namely, bond polarity, molecular shape, polarity of molecules, lattices, intermolecular forces, and the octet rule. The diagnostic instrument was administered to a total of 243 grade-11 and -12 chemistry students and has a Cronbach alpha reliability of 0.73. Item difficulties ranged from 0.13 to 0.60; discrimination values ranged from 0.32 to 0.65. Each item was analyzed to ascertain student understanding of and identify misconceptions related to the concepts and propositional statements underlying covalent bonding and structure.  相似文献   

3.
Two reasons are suggested for studying the degree of conceptual integration in student thinking. The linking of new material to existing knowledge is an important aspect of meaningful learning. It is also argued that conceptual coherence is a characteristic of scientific knowledge and a criterion used in evaluating new theories. Appreciating this ‘scientific value’ should be one objective when students learn about the nature of science. These considerations imply that students should not only learn individual scientific models and principles, but should be taught to see how they are linked together. The present paper describes the use of an interview protocol designed to explore conceptual integration across two college‐level subjects (chemistry and physics). The novelty here is that a single interview is used to elicit explanations of a wide range of phenomena. The potential of this approach is demonstrated through an account of one student's scientific thinking, showing both how she applied fundamental ideas widely, and also where conceptual integration was lacking. The value and limitations of using this type of interview as one means for researching conceptual integration in students' thinking are discussed.  相似文献   

4.
Abstract

The nature of physics as a scientific discipline is largely determined by the models of reality it utilizes. It is therefore appropriate that teachers of physics have a sound knowledge of the origin and nature of these models, their functions and the role they play in the development of the discipline. The results of a study with regard to the perceptions of models held by prospective physical science (a combination of physics and chemistry) teachers studying at South African universities are reported in this paper. The overall conclusion drawn from the study is that these students are far from prepared to incorporate models properly in their teaching. General misconceptions about models have also been identified. These misconceptions can have far‐reaching effects on the structuring of the physics knowledge of pupils exposed to them.  相似文献   

5.
This study replicates, with additions, research done by Garnett and Treagust. Garnett and Treagust's interview questions for galvanic and electrolytic cells were used with modifications; concentration cell questions were asked in a similar manner. These questions were administered to 16 introductory college chemistry students after electrochemistry instruction. Student misconceptions most commonly encountered included notions that electrons flow through the salt bridge and electrolyte solutions to complete the circuit, plus and minus signs assigned to the electrodes represent net electronic charges, and water is unreactive in the electrolysis of aqueous solutions. New misconceptions identified included notions that half-cell potentials are absolute and can be used to predict the spontaneity of individual half-cells, and electrochemical cell potentials are independent of ion concentrations. Most students demonstrating misconceptions were still able to calculate cell potentials correctly, which is consistent with research suggesting that students capable of solving quantitative examination problems often lack an understanding of the underlying concepts. Probable origins of these student misconceptions were attributed to students being unaware of the relative nature of electrochemical potentials and chemistry textbooks making misleading and incorrect statements. A minor technical flaw in the Garnett and Treagust study is also addressed. J Res Sci Teach 34: 377–398, 1997.  相似文献   

6.
This study involved the development and application of a two-tier diagnostic test measuring college biology students' understanding of diffusion and osmosis after a course of instruction. The development procedure had three general steps: defining the content boundaries of the test, collecting information on students' misconceptions, and instrument development. Misconception data were collected from interviews and multiple-choice questions with free response answers. The data were used to develop 12 two-tier multiple choice items in which the first tier examined content knowledge and the second examined understanding of that knowledge. The conceptual knowledge examined was the particulate and random nature of matter, concentration and tonicity, the influence of life forces on diffusion and osmosis, membranes, kinetic energy of matter, the process of diffusion, and the process of osmosis. The diagnostic instrument was administered to 240 students (123 non-biology majors and 117 biology majors) enrolled in a college freshman biology laboratory course. The students had completed a unit on diffusion and osmosis. The content taught was carefully defined by propositional knowledge statements, and was the same content that defined the content boundaries of the test. The split-half reliability was .74. Difficulty indices ranged from 0.23 to 0.95, and discrimination indices ranged from 0.21 to 0.65. Each item was analyzed to determine student understanding of, and identify misconceptions about, diffusion and osmosis.  相似文献   

7.
Science education studies have revealed that students often have misconceptions about how nature works, but what happens to misconceptions after a conceptual change remains poorly understood. Are misconceptions rejected and replaced by scientific conceptions, or are they still present in students' minds, coexisting with newly acquired scientific conceptions? In this study, we use functional magnetic resonance imaging (fMRI) to compare brain activation between novices and experts in science when they evaluate the correctness of simple electric circuits. Results show that experts, more than novices, activate brain areas involved in inhibition when they evaluate electric circuits in which a bulb lights up, even though there is only one wire connecting it to the battery. These findings suggest that experts may still have a misconception encoded in the neural networks of their brains that must be inhibited in order to answer scientifically.  相似文献   

8.
Research suggests that conventional teaching techniques have proved largely ineffective for dealing with the problem of science students’ misconceptions or alternative frameworks. This paper reports an investigation whereby inter‐personal conflict within dyadic interactions is used as a strategy for promoting development towards correct scientific conceptions in specific areas of electrical circuits and mechanics amongst first‐year tertiary physics students. The data indicate that a large number of physics students at the tertiary level hold non‐scientific conceptions of these physical phenomena. The dyadic interaction strategy proved effective as a means of encouraging students to actively and closely consider their own thinking about basic physical concepts. Further, results highlight the importance of inter‐personal conflict in the process of conceptual change.  相似文献   

9.
Self-explanation in the domain of statistics: an expertise reversal effect   总被引：1，自引：0，他引：1  
This study investigated the effects of four instructional methods on cognitive load, propositional knowledge, and conceptual understanding of statistics, for low prior knowledge students and for high prior knowledge students. The instructional methods were (1) a reading-only control condition, (2) answering open-ended questions, (3) answering open-ended questions and formulating arguments, and (4) studying worked-out examples of the type of arguments students in the third group had to formulate themselves. The results indicate that high prior knowledge students develop more propositional knowledge of statistics than low prior knowledge students. With regard to conceptual understanding, the results indicate an expertise reversal effect: low prior knowledge students learn most from studying worked-out examples, whereas high prior knowledge students profit most from formulating arguments. Thus, novice students should be guided into the subject matter by means of worked-out examples. As soon as students have developed more knowledge of the subject matter, they should be provided with learning tasks that stimulate students to solve problems by formulating arguments.  相似文献   

10.
The purpose of this study was to investigate the effects of conceptual assignments and conceptual change discussions on students' achievement and misconceptions about force and motion. The study was conducted with 6 physics teachers and their 18 classes, consisting of 396 high school physics students. The teachers administered the Force Misconception and Force Achievement Tests to their physics classes as a pretest. The results obtained were used to match the 18 classes statistically. Students assigned to the conceptual assignment protocol completed five conceptual assignments about force and motion. Students assigned to the discussion method participated in conceptual change discussions. At the end of the 8‐week treatment period, the same tests were administered to all students as a posttest. The data were analyzed by using multivariate analysis of covariance, followed by protected univariate F test and step‐down analysis. The statistical results showed that the conceptual change discussion was an effective means of reducing the number of misconceptions students held about force and motion. The conceptual change discussion was also found significantly effective in improving students' achievement in force and motion. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 1001–1015, 2002  相似文献   

11.
This study describes the development and validation of a three-tier multiple-choice diagnostic test, the atmosphere-related environmental problems diagnostic test (AREPDiT), to reveal common misconceptions of global warming (GW), greenhouse effect (GE), ozone layer depletion (OLD), and acid rain (AR). The development of a two-tier diagnostic test procedure as described by Treagust constitutes the framework for this study. To differentiate a lack of knowledge from a misconception, a certainty response index is added as a third tier to each item. Based on propositional knowledge statements, related literature, and the identified misconceptions gathered initially from 157 pre-service teachers, the AREPDiT was constructed and administered to 256 pre-service teachers. The Cronbach alpha reliability coefficient of the pre-service teachers’ scores was estimated to be 0.74. Content and face validations were established by senior experts. A moderate positive correlation between the participants’ both-tiers scores and their certainty scores indicated evidence for construct validity. Therefore, the AREPDiT is a reliable and valid instrument not only to identify pre-service teachers’ misconceptions about GW, GE, OLD, and AR but also to differentiate these misconceptions from lack of knowledge. The results also reveal that a majority of the respondents demonstrated limited understandings about atmosphere-related environmental problems and held six common misconceptions. Future studies could test the AREPDiT as a tool for assessing the misconceptions held by pre-service teachers from different programs as well as in-service teachers and high school students.  相似文献   

12.
Many studies have previously focused on how people with different levels of expertise solve physics problems. In early work, focus was on characterising differences between experts and novices and a key finding was the central role that propositionally expressed principles and laws play in expert, but not novice, problem-solving. A more recent line of research has focused on characterising continuity between experts and novices at the level of non-propositional knowledge structures and processes such as image-schemas, imagistic simulation and analogical reasoning. This study contributes to an emerging literature addressing the coordination of both propositional and non-propositional knowledge structures and processes in the development of expertise. Specifically, in this paper, we compare problem-solving across two levels of expertise—undergraduate students of chemistry and Ph.D. students in physical chemistry—identifying differences in how conceptual metaphors (CMs) are used (or not) to coordinate propositional and non-propositional knowledge structures in the context of solving problems on entropy. It is hypothesised that the acquisition of expertise involves learning to coordinate the use of CMs to interpret propositional (linguistic and mathematical) knowledge and apply it to specific problem situations. Moreover, we suggest that with increasing expertise, the use of CMs involves a greater degree of subjective engagement with physical entities and processes. Implications for research on learning and instructional practice are discussed.  相似文献   

13.
In this study, the Turkish students' understanding level of electric circuits consisting of two bulbs and one battery was investigated by using open-ended questions. Two-hundred fifty students, whose ages range from 11 to 22, were chosen from five different groups at primary, secondary and university levels in Trabzon in Turkey. In analyzing students' drawings and explanations, both qualitative and quantitative methodologies were exploited. The unipolar model (Model A), the clashing currents model (Model B), the current consumed model (Model C) and the scientist model with current conserved (Model D) determined from the related literature were used to categorize the students' answers. The results showed that the Turkish students have many misconceptions about electric circuits. Also, it is found out that especially Model A was widespread accepted among the students in group 1 (5th grade) and half of the students in group 3 (9th grade) has an understanding of electric circuits as it is in Model C.  相似文献   

14.
《学习科学杂志》2013,22(2):201-238
This study explores how novices' conceptions about electric circuits affected their self-directed experimentation in a computer-based circuit laboratory. The participants, 22 undergraduates with no formal college instruction in physics, worked individually on an initial problem to assess their conceptual models of circuits and in subsequent sessions on open-ended experimentation with the computer laboratory, attempted to rediscover the laws of electric circuits. Analysis of the initial problem identified four conceptual models in students' solutions. Lower level models were local, piecemeal, and represented the surface features of the materials, whereas higher level models were progressively more cohesive, integrated, and principled. Relations were found between students' causal models and their learning gains in the computer laboratory. Good and poor learners with the laboratory were identified; these groups showed strategic differences in goal-directed planning, generating and interpreting evidence, and managing data. In general, sophisticated models in the initial problem were related to sophisticated reasoning in the computer discovery task. It is suggested that research oriented to the improvement of science learning should attend to interactive relationships between prior conceptions, inference strategies, and the structure of domain-specific knowledge.  相似文献   

15.
This paper describes a newly adapted instrument for measuring novice-to-expert-like perceptions about biology: the Colorado Learning Attitudes about Science Survey for Biology (CLASS-Bio). Consisting of 31 Likert-scale statements, CLASS-Bio probes a range of perceptions that vary between experts and novices, including enjoyment of the discipline, propensity to make connections to the real world, recognition of conceptual connections underlying knowledge, and problem-solving strategies. CLASS-Bio has been tested for response validity with both undergraduate students and experts (biology PhDs), allowing student responses to be directly compared with a consensus expert response. Use of CLASS-Bio to date suggests that introductory biology courses have the same challenges as introductory physics and chemistry courses: namely, students shift toward more novice-like perceptions following instruction. However, students in upper-division biology courses do not show the same novice-like shifts. CLASS-Bio can also be paired with other assessments to: 1) examine how student perceptions impact learning and conceptual understanding of biology, and 2) assess and evaluate how pedagogical techniques help students develop both expertise in problem solving and an expert-like appreciation of the nature of biology.  相似文献   

16.
The aim of this paper is to describe a novel modeling and simulation package, connected chemistry, and assess its impact on students' understanding of chemistry. Connected chemistry was implemented inside the NetLogo modeling environment. Its design goal is to present a variety of chemistry concepts from the perspective of emergent phenomena—that is, how macro-level patterns in chemistry result from the interactions of many molecules on a submicro-level. The connected chemistry modeling environment provides students with the opportunity to observe and explore these interactions in a simulated environment that enables them to develop a deeper understanding of chemistry concepts and processes in both the classroom and laboratory. Here, we present the conceptual foundations of instruction using connected chemistry and the results of a small study that explored its potential benefits. A three-part, 90-min interview was administered to six undergraduate science majors regarding the concept of chemical equilibrium. Several commonly reported misconceptions about chemical equilibrium arose during the interview. Prior to their interaction with connected chemistry, students relied on memorized facts to explain chemical equilibrium and rigid procedures to solve chemical equilibrium problems. Using connected chemistry students employed problem-solving techniques characterized by stronger attempts at conceptual understanding and logical reasoning.  相似文献   

17.
《学习科学杂志》2013,22(1):69-105
Several earlier studies have found the amount learned while studying worked-out examples is proportional to the number of self-explanations generated while studying examples. A self-explanation is a comment about an example statement that contains domain-relevant information over and above what was stated in the example line itself. This article analyzes the specific content of self-explanations generated by students while studying physics examples. In particular, the content is analyzed into pieces of constituent knowledge that were used in the comments. These were further analyzed in order to trace the source of knowledge from which self-explanations could be generated. The results suggest that there are two general sources for self-explanations. The first is deduction from knowledge acquired earlier while reading the text part of the chapter, usually by simply instantiating a general principle, concept, or procedure with information in the current example statement. The second explanation is generalization and extension of the example statements. Such construction of the content of the example statements yield new general knowledge that helps complete the students' otherwise incomplete understanding of the domain principles and concepts. The relevance of this research for instruction and models of explanation-based learning is discussed.  相似文献   

18.
This study examines differences in conceptual knowledge representations among three groups of students with different levels of study of chemistry. Variation in the structural characteristics of participants’ concept maps on the topic of acid-base equilibrium were sought by indirect means. Year 12 secondary chemistry students, undergraduate chemistry majors and honours, masters and doctoral candidates participated in the study. Paired propositional links in the concept maps for the three groups were analysed by the scaling algorithms “Pathfinder” and multidimensional scaling. Results show differences among groups in the structural significance in the networks of abstract process-related nodes and matter-related nodes. Implications for theories of conceptual change are discussed.  相似文献   

19.
This article explores the effectiveness of intervention discussion sections for a college general chemistry course designed to apply research on student preconceptions, knowledge integration, and student explanation. Two interventions, on bond energy and spontaneity, were tested and intervention student performance was compared with that of a control group that did not use the experimental pedagogy. Results indicate that this instruction, which identifies students' initial conceptions and integrates those ideas into class discussion, leads to enhanced conceptual understanding. The intervention group outperformed the control group on a written course midterm, the thermodynamics portion of a standardized American Chemical Society examination, and an in‐depth interview. In interviews, the intervention group students explained the energetics of bond breaking and formation at a more sophisticated level than did the control students. In contrast, control students were more tenuous in their thinking, tended to contradict themselves more when discussing bond energy, and harbored more misconceptions about spontaneity. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 464–496, 2002  相似文献   

20.
Many students in secondary schools consider the sciences difficult and unattractive. This applies to physics in particular, a subject in which students attempt to learn and understand numerous theoretical concepts, often without much success. A case in point is the understanding of the concepts current, voltage and resistance in simple electric circuits. In response to these problems, reform initiatives in education strive for a change of the classroom culture, putting emphasis on more authentic contexts and student activities containing elements of inquiry. The challenge then becomes choosing and combining these elements in such a manner that they foster an understanding of theoretical concepts. In this article we reflect on data collected and analyzed from a series of 12 grade 9 physics lessons on simple electric circuits. Drawing from a theoretical framework based on individual (conceptual change based) and socio-cultural views on learning, instruction was designed addressing known conceptual problems and attempting to create a physics (research) culture in the classroom. As the success of the lessons was limited, the focus of the study became to understand which inherent characteristics of inquiry based instruction complicate the process of constructing conceptual understanding. From the analysis of the data collected during the enactment of the lessons three tensions emerged: the tension between open inquiry and student guidance, the tension between students developing their own ideas and getting to know accepted scientific theories, and the tension between fostering scientific interest as part of a scientific research culture and the task oriented school culture. An outlook will be given on the implications for science lessons.  相似文献   

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