Physics students' understanding of relative speed: A phenomenographic study

It is important that students of physics develop both quantitative and qualitative understanding of physical concepts and principles. Although accuracy and reliability in solving quantitative problems is necessary, a qualitative understanding is required in applying concepts and principles to new problems and in real-life situations. If students are not able to understand what underlies quantitative problem-solving procedures nor interpret the solution in physical terms, it is questionable whether they have developed an adequate understanding of physics. The research reported here is part of a larger phenomenographic study that is concerned with the assessment of physics students' understanding of some basic concepts and principles in kinematics. In this article students' understanding of the concept of relative speed is described. A variety of ways of understanding relative speed and of viewing a problem that dealt with this concept were uncovered. The results are used to suggest ways for teachers to proceed in assisting students to enhance their understanding of this concept. The teaching principles outlined concern both teaching relative speed, in particular, and teaching scientific concepts and principles, more generally.     

Varying Use of Conceptual Metaphors across Levels of Expertise in Thermodynamics

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.     

Problem solving and chemical equilibrium: Successful versus unsuccessful performance

The purpose of this study was to describe the problem-solving behaviors of experts and novices engaged in solving seven chemical equilibrium problems. Thirteen novices (five high-school students, five undergraduate majors, and three nonmajors) and ten experts (six doctoral students and four faculty members) were videotaped as they individually solved standard chemical equilibrium problems. The nature of the problems was such that they required more than mere recall or algorithmic learning and yet simple enough to provide the novices a reasonable chance of solving them. Extensive analysis of the think-aloud protocols produced 27 behavioral tendencies that can be used to describe and differentiate between successful and unsuccessful problem solvers. Successful solvers' perceptions of the problem were characterized by careful analysis and reasoning of the task, use of related principles and concepts to justify their answers, frequent checks of the consistency of answers and reasons, and better quality of procedural and strategic knowledge. Unsuccessful subjects had many knowledge gaps and misconceptions about the nature of chemical equilibrium. Even faculty experts were sometimes unable to correctly apply common chemical principles during the problem-solving process. Important theoretical concepts such as molar enthalpy, heat of reaction, free energy of formation, and free energy of reaction were rarely used by novices in explaining problems.     

Expertise and the organization of knowledge: Unexpected differences among genetic counselors,faculty, and students on problem categorization tasks

Chi, Feltovich, and Glaser (1981) observed that experts (physics faculty) organized problems into groups according to the underlying physics law or principle applicable, whereas the groupings of novice physics students focused on objects, literal physics terms, and physical configurations in the problems. Replication of these findings in a number of similar studies has led to the general acceptance of the proposition that the mental schemes used by experts to organize information within a content domain are organized according to the “deep structure” of the domain, whereas the schemes of novices are bound by “surface” dimensions. Categorizations of genetics problems produced by genetics counselor and faculty experts in comparison to student novices obtained in the present study, however, are inconsistent with a deep structure/surface structure dichotomy. As expected, faculty experts focused almost exclusively on conceptual principles, but student sorts focused primarily on problem knowns and unknowns. The expert counselor sortings unexpectedly resembled those of the students in this regard. Counselors also emphasized solution techniques to be used, whereas students emphasized the verbatim wording of the problem statement. These findings are consistent with the hypothesis that as expertise is attained, a person restructures his/her knowledge of the domain into a framework that is based on critical dimensions that facilitate the daily use of that knowledge. Implications for theoreticians, researchers, and teachers are drawn. Whenever possible, future studies of expertise should include noneducator experts; teachers should help students develop the ability to construct and reconstruct the organizational frameworks of their knowledge so as to facilitate the effective use of that knowledge in the face of change.     

Understanding student pathways in context-rich problems

This paper describes the ways that students’ problem-solving behaviors evolve when solving multi-faceted, context-rich problems within a web-based learning environment. During the semester, groups of two or three students worked on five physics problems that required drawing on more than one concept and, hence, could not be readily solved with simple “plug-and-chug” strategies. The problems were presented to students in a data-rich, online problem-based learning environment that tracked which information items were selected by students as they attempted to solve the problem. The students also completed a variety of tasks, like entering an initial qualitative analysis of the problem into an online form. Students were not constrained to complete these tasks in any specific order. As they gained more experience in solving context-rich physics problems, student groups showed some progression towards expert-like behavior as they completed qualitative analysis earlier and were more selective in their perusal of informational resources. However, there was room for more improvement as approximately half of the groups still completed the qualitative analysis task towards the end of the problem-solving process rather than at the beginning of the task when it would have been most useful to their work.     

Design and Application of Interactive Simulations in Problem-Solving in University-Level Physics Education

In recent years, interactive computer simulations have been progressively integrated in the teaching of the sciences and have contributed significant improvements in the teaching–learning process. Practicing problem-solving is a key factor in science and engineering education. The aim of this study was to design simulation-based problem-solving teaching materials and assess their effectiveness in improving students’ ability to solve problems in university-level physics. Firstly, we analyze the effect of using simulation-based materials in the development of students’ skills in employing procedures that are typically used in the scientific method of problem-solving. We found that a significant percentage of the experimental students used expert-type scientific procedures such as qualitative analysis of the problem, making hypotheses, and analysis of results. At the end of the course, only a minority of the students persisted with habits based solely on mathematical equations. Secondly, we compare the effectiveness in terms of problem-solving of the experimental group students with the students who are taught conventionally. We found that the implementation of the problem-solving strategy improved experimental students’ results regarding obtaining a correct solution from the academic point of view, in standard textbook problems. Thirdly, we explore students’ satisfaction with simulation-based problem-solving teaching materials and we found that the majority appear to be satisfied with the methodology proposed and took on a favorable attitude to learning problem-solving. The research was carried out among first-year Engineering Degree students.     

Expert and novice solutions of genetic pedigree problems

This study compared the problem-solving performance of university genetics professors and genetics students, and therefore fits the expert versus novice paradigm. The subjects solved three genetic pedigree problems. Data were gathered using standard think-aloud protocol procedures. Although the experts did not differ from the novices in terms of the number of correct solutions obtained, there were significant differences favoring the experts in terms of the completeness and conclusiveness of the solutions. The experts identified more critical cues in the pedigrees which were used to generate and test hypotheses, they tested more hypotheses by assigning genotypes to individuals in the pedigrees, and were more rigorous than the novices in the falsification of alternative hypotheses. The experts varied their problem-solving strategy to suit the particular conditions of problems involving rare or common traits. Novices did nor recognize the need to make such modifications to their strategies.     

The Effect of Hints and Model Answers in a Student-Controlled Problem-Solving Program for Secondary Physics Education

Many students experience difficulties in solving applied physics problems. Most programs that want students to improve problem-solving skills are concerned with the development of content knowledge. Physhint is an example of a student-controlled computer program that supports students in developing their strategic knowledge in combination with support at the level of content knowledge. The program allows students to ask for hints related to the episodes involved in solving a problem. The main question to be answered in this article is whether the program succeeds in improving strategic knowledge by allowing for more effective practice time for the student (practice effect) and/or by focusing on the systematic use of the available help (systematic hint-use effect). Analysis of qualitative data from an experimental study conducted previously show that both the expected effectiveness of practice and the systematic use of episode-related hints account for the enhanced problem-solving skills of students.     

The Missing Curriculum in Physics Problem-Solving Education

Physics is often seen as an excellent introduction to science because it allows students to learn not only the laws governing the world around them, but also, through the problems students solve, a way of thinking which is conducive to solving problems outside of physics and even outside of science. In this article, we contest this latter idea and argue that in physics classes, students do not learn widely applicable problem-solving skills because physics education almost exclusively requires students to solve well-defined problems rather than the less-defined problems which better model problem solving outside of a formal class. Using personal, constructed, and the historical accounts of Schrödinger’s development of the wave equation and Feynman’s development of path integrals, we argue that what is missing in problem-solving education is practice in identifying gaps in knowledge and in framing these knowledge gaps as questions of the kind answerable using techniques students have learned. We discuss why these elements are typically not taught as part of the problem-solving curriculum and end with suggestions on how to incorporate these missing elements into physics classes.     

Contextual and strategic knowledge in the acquisition of design expertise

This study examines the acquisition of expertise in designing and developing information systems. The aim was to investigate how practical experience is related to contextual and strategic knowledge in problem-solving. Using a combination of expert–novice comparisons and longitudinal methods, professional systems analysts were compared with novices at the beginning and end of a seven month project-based course. The results show that during the course, the novices acquired a good deal of strategic competence in using domain-specific methods. Compared to the novices, the experts showed a more comprehensive and higher level of awareness of clients' contextual constraints. The study demonstrated qualitative variation in the subjects' solutions to design problems. Five distinct solution patterns were found; these appeared to originate mainly from the settings of the subjects' practical work.     

Differences in the problem solving of stronger and weaker novices in physics: Knowledge,strategies, or knowledge structure?

This study investigates the extent to which differences in the problem-solving performance of stronger and weaker novices in physics arise from: (a) differences in amount of domain knowledge, (b) differences in how domain knowledge is organized, and (c) differences in the strategic application of domain knowledge. Ten first-year university physics students attempted to solve one easy and one difficult problem involving Newton's second law. Clear differences in the protocols of stronger and weaker students for the difficult problem, combined with successful performance by all students on the easy problem, were interpreted as evidence for differences in the organization of relevant knowledge held by more versus less successful first-year physics students. Some differences in procedural knowledge were also observed, but all students used the working forward strategy that had been presented to them in lectures.     

Impacts of learning inventive problem-solving principles: students’ transition from systematic searching to heuristic problem solving

This paper presents the outcomes of teaching an inventive problem-solving course in junior high schools in an attempt to deal with the current relative neglect of fostering students’ creativity and problem-solving capabilities in traditional schooling. The method involves carrying out systematic manipulation with attributes, functions and relationships between existing components and variables in a system. The 2-year research study comprised 112 students in the experimental group and 100 students in the control group. The findings indicated that in the post-course exam, the participants suggested a significantly greater number of original and useful solutions to problems presented to them compared to the pre-course exam and to the control group. The course also increased students’ self-beliefs about creativity. Although at the beginning of the course, the students adhered to ‘systematic searching’ using the inventive problem-solving principles they had learned, later on they moved to ‘semi-structured’ and heuristic problem solving, which deals with using strategies, techniques, rules-of-thumb or educated guessing in the problem-solving process. It is important to note, however, that teaching the proposed method in school should take place in the context of engaging students in challenging tasks and open-ended projects that encourage students to develop their ideas. There is only little benefit in merely teaching students inventive problem-solving principles and letting them solve discrete pre-designed exercises.     

Problem solving and classical genetics: Successful versus unsuccessful performance

Expert-novice problem-solving research is extended in this study to include classical genetics. Eleven undergraduates (novices) and nine graduate students and instructors (experts) were videotaped as they solved moderately complex genetics problems. Detailed analysis of these “think aloud” protocols resulted in 32 common tendencies that could be used to differentiate between successful and unsuccessful problem solvers. Experts perceive a problem as a task requiring analysis and reasoning and they tend to use a knowledge-development (forward-working) approach. They make frequent checks on the correctness of their work, use accurate and detailed bookkeeping procedures, and have a broader range of heuristics to apply to the problem. It is clear that studying problem solving using the expert/novice design requires that the problems be difficult enough to require more than more recall and yet simple enough to allow novices a chance for solution. Applying elementary probability concepts seemed to be the most difficult aspect of many of the genetics problems, even for the experts.     

谈解决物理问题能力的培养

高三物理复习教学中应注意培养学生会运用特殊的解题方法使自己的知识结构形成一个较为完整的有机的整体,从而提高学生解决物理实际问题的能力。物理解题方法有:求异思维法、假设法、类似模型法、变换参照系法、情景图象法和对称法等。     

Using a computer simulation to compare expert/novice problem-solving subroutines

Hierarchical problem-solving strategies employed in solving exercise science problems were examined in this study, which also tested the validity of an educational computer simulation. Hypothesis testing was used as the theoretical base for the study of differences in problem-solving within the computer simulation. In a previous study two groups of undergraduate (novices) and graduate students were compared in their ability to solve exercise science problems. The present study added a group of faculty (experts) who were presented with the same simulation protocol as the other subjects. Protocol analysis and the Pitt coding system were used to analyse verbal data. Group differences were examined statistically. The faculty were superior in interpreting data and used the Basic Heuristic and Pattern Extraction strategies for the generation and use of algorithms. The problem-solving strategies varied for each group based on the perceived difficulty of the problem, the knowledge base available, and the similarity of the given problem to previous problems.     

运用"量"的概念提高定性分析实验成功率

对学生在定性分析实验中存在的问题进行了分析，提出在定性分析实验中让学生建立量的概念，从而提高定性分析实验的成功率。     

Project physics in N.S.W.

Conclusions Of all the aspects of classroom environment studied in this research, attention to the social relevance of physics had one of the strongest associations, in a positive sense, with each of the student outcomes. The research showed that positive student outcomes tended to be closely associated with low levels of frustration. Integration of experimental and theoretical aspects of physics tended to be accompanied by positive student outcomes. The integration could well go beyond using experiments merely to illustrate and/or verify principles and theories previously taught. At least in some topics, student understanding of physics could well follow upon and be the outcome of experiences gained during practical work, and some problem-solving by experiments could be given. Despite some inveitable tensions, teachers who favoured student autonomy were generally satisfied with their physics teaching. Moreover, their students reported more growth in personal development areas such as a sense of responsibility than did students who did not experience much autonomy. The multi-media characteristics of Project Physics makes it a particularly suitable approach for including student autonomy. The results indicated that academic achievement is not likely to suffer when attention is given to encouraging student initiative, sense of responsibility, improved study methods and persistence at a task. Such goals are long-term goals and working towards them tends to be accompanied by greater interest in and enjoyment of physics.     

Students’ Perceptions of Dynamics Concept Pairs and Correlation with Their Problem-Solving Performance

A concept pair is a pair of concepts that are fundamentally different but closely related. To develop a solid conceptual understanding in dynamics (a foundational engineering science course) and physics, students must understand the fundamental difference and relationship between two concepts that are included in each concept pair. However, all existing research in dynamics and physics education has been focused on the identification and repair of students?? misunderstanding of individual concepts, but not concept pairs. The present research fills the gap of existing research by studying students?? perceptions of dynamics concept pairs and correlation with their problem-solving performance in both particle and rigid-body dynamics. A total of 88 engineering undergraduate students participated in the present study. Students?? perceptions were assessed using a 40-item instrument that included 20 dynamics concept pairs at fundamental Level One and higher-order Level Two. Students?? problem-solving performance was assessed using four exams that included 66 dynamics problems. The coefficients of reliability (Cronbach??s ??) of assessment instruments vary between 0.69 and 0.93. The research findings from the present study show that students were not confident in their understanding of Level-Two concept pairs, especially the relationship between the Principle of Linear Impulse and Momentum and the Principle of Angular Impulse and Momentum, and the relationship between the Principle of Angular Impulse and Momentum and the Conservation of Angular Momentum. A statistically significant correlation exists between students?? perceptions of Level-Two concept pairs and their problem-solving performance on both particle dynamics (r?=?0.355, p?<?0.01) and rigid-body dynamics (r?=?0.351, p?<?0.01). The research findings made from the present study imply that educational efforts should be focused on improving students?? understanding of Level-Two dynamics concept pairs.     

How Can We Improve Problem Solving in Undergraduate Biology? Applying Lessons from 30 Years of Physics Education Research

If students are to successfully grapple with authentic, complex biological problems as scientists and citizens, they need practice solving such problems during their undergraduate years. Physics education researchers have investigated student problem solving for the past three decades. Although physics and biology problems differ in structure and content, the instructional purposes align closely: explaining patterns and processes in the natural world and making predictions about physical and biological systems. In this paper, we discuss how research-supported approaches developed by physics education researchers can be adopted by biologists to enhance student problem-solving skills. First, we compare the problems that biology students are typically asked to solve with authentic, complex problems. We then describe the development of research-validated physics curricula emphasizing process skills in problem solving. We show that solving authentic, complex biology problems requires many of the same skills that practicing physicists and biologists use in representing problems, seeking relationships, making predictions, and verifying or checking solutions. We assert that acquiring these skills can help biology students become competent problem solvers. Finally, we propose how biology scholars can apply lessons from physics education in their classrooms and inspire new studies in biology education research.