arXiv subjects

Chandralekha Singh

Publications and source records attributed to Chandralekha Singh.

At least 163 records · Page 9Linked to original sources

arXiv2016

Using Categorization of Problems as an Instructional Tool to Help Introductory Students Learn Physics

The ability to categorize problems based upon underlying principles, rather than contexts, is considered a hallmark of expertise in physics problem solving. With inspiration from a classic study by Chi, Feltovich, and Glaser, we compared the categorization of 25 introductory mechanics problems based upon similarity of solution by students in large calculus-based introductory courses with physics faculty and Ph.D. students. Here, we summarize the study and suggest that a categorization task, especially when conducted with students working with peers in small groups, can be an effective pedagogical tool to help students in introductory physics courses learn to discern the underlying similarity between problems with diverse contexts but the same underlying physics principles.

physics.ed-ph↗

arXiv2016

Learning from mistakes: The effect of students' written self-diagnoses on subsequent problem solving

Helping students learn to think like a physicist is an important goal of many introductory physics courses. One characteristic distinguishing more experienced physicists from novice students is that they make better use of problem solving as a learning opportunity. Experts were found to spend more time than novices in monitoring their work, reflecting upon their possibly deficient approach to solving a problem, reconsidering their choices as necessary, and extending and refining their knowledge structure. Moreover, research on worked-out examples suggests that better performing students are those who self-explain, that is, elaborate to themselves what they are learning from those examples, generate inferences, acknowledge mismatches between their own approach and that of the example, and attempt to resolve conflicts (self-repair). Indeed, physics instructors often express concern that many students do not make an effort to learn from their mistakes after the graded problems are returned to them. Here, we discuss an investigation focusing on how well introductory physics students self-diagnose their mistakes in their quiz solutions and its effect on subsequent problem solving in different interventions.

physics.ed-ph↗

arXiv2016

Introduction to physics teaching for science and engineering undergraduates

Recruiting and retaining highly qualified physics and physical science teachers is critical for maintaining America's global competitiveness. Unfortunately, only one third of the high school teachers in physics have a degree in physics and an even smaller number of physical science teachers in middle school have a good grasp of the scientific content they teach. Moreover, teachers often lack adequate pedagogical content knowledge to teach science effectively. Here, we discuss the development, implementation, and assessment of a course for science and engineering undergraduates designed to increase awareness and help them develop an interest and a deeper appreciation of the intellectual demands of physics teaching. The course focused on increasing student enthusiasm and confidence in teaching by providing well supported teaching opportunities and exposure to physics education research. The course assessment methods include 1) pre/post-test measures of attitude and expectations about science teaching, 2) self and peer evaluation of student teaching, 3) content-based pre/post-tests given to students who received instruction from the student teachers, and 4) audio-taped focus group discussions in the absence of the instructor and TA to evaluate student perspective on different aspects of the course and its impact.

physics.ed-ph↗

arXiv2016

Helping Students Learn Quantum Mechanics for Quantum Computing

Quantum information science and technology is a rapidly growing interdisciplinary field drawing researchers from science and engineering fields. Traditional instruction in quantum mechanics is insufficient to prepare students for research in quantum computing because there is a lack of emphasis in the current curriculum on quantum formalism and dynamics. We are investigating the difficulties students have with quantum mechanics and are developing and evaluating quantum interactive learning tutorials (QuILTs) to reduce the difficulties. Our investigation includes interviews with individual students and the development and administration of free-response and multiple-choice tests. We discuss the implications of our research and development project on helping students learn quantum mechanics relevant for quantum computing.

physics.ed-ph↗

arXiv2016

Improving Students' Understanding of Quantum Measurement Part 2: Development of Research-based Learning Tools

We describe the development and implementation of research-based learning tools such as the Quantum Interactive Learning Tutorials (QuILTs) and peer instruction tools to reduce students' common difficulties with issues related to measurement in quantum mechanics. A preliminary evaluation shows that these learning tools are effective in improving students' understanding of concepts related to quantum measurement.

physics.ed-ph↗

arXiv2016

When physical intuition fails

We analyze the problem solving strategies of physics professors in a case where their physical intuition fails. A non-intuitive introductory-level problem was identified and posed to twenty physics professors. The problem placed the professors in a situation often encountered by students, and their response highlights the importance of intuition and experience in problem solving. While professors had difficulty in solving the problem under the time constraint, they initially employed a systematic approach, e.g., visualizing the problem, considering various conservation laws, and examining limiting cases. After finding that familiar techniques were not fruitful, they made incorrect predictions based on one of two equally important factors. By contrast, other more familiar problems that require the consideration of two important principles (e.g., conservation of both energy and momentum for a ballistic pendulum) are quickly solved by the same professors. The responses of students who were given the same problem reflected no overarching strategies or systematic approaches, and a much wider variety of incorrect responses were given. This investigation highlights the importance of teaching effective problem solving heuristics, and suggests that instructors assess the difficulty of a problem from the perspective of beginning students.

physics.ed-ph↗

arXiv2016

Student understanding of quantum mechanics at the beginning of graduate instruction

A survey was developed to probe student understanding of quantum mechanics at the beginning of graduate instruction. The survey was administered to 202 physics graduate students enrolled in first-year quantum mechanics courses from seven universities at the beginning of the first semester. We also conducted one-on-one interviews with fifteen graduate or advanced undergraduate students who had just completed a course in which all the content on the survey was covered. Although students from some universities performed better on average than others, we found that students share universal difficulties understanding the concepts of quantum mechanics. The difficulties were often due to over-generalizations of concepts learned in one context to other contexts where they are not directly applicable. Difficulties in distinguishing between closely related concepts and making sense of the formalism of quantum mechanics were common. The results of this study can sensitize instructors of first-year graduate quantum physics to some of the difficulties students are likely to face.

physics.ed-ph↗

arXiv2016

Assessing Student Expertise in Introductory Physics with Isomorphic Problems, Part I: Performance on Non-intuitive Problem Pair from Introductory Physics

Investigations related to expertise in problem solving and ability to transfer learning from one context to another are important for developing strategies to help students perform more expert-like tasks. Here we analyze written responses to a pair of non-intuitive isomorphic problems given to introductory physics students and discussions with a subset of students about them. Students were asked to explain their reasoning for their written responses. We call the paired problems isomorphic because they require the same physics principle to solve them. However, the initial conditions are different and the frictional force is responsible for increasing the linear speed of an object in one of the problems while it is responsible for decreasing the linear speed in the other problem. We categorize student responses and evaluate student performance within the context of their evolving expertise. We compare and contrast the patterns of student categorization for the two isomorphic problems. We discuss why certain incorrect responses were better than others and shed light on the evolution of students' expertise. We compare the performance of students who worked on both isomorphic problems with those who worked only on one of the problems to understand whether students recognized their underlying similarity and whether isomorphic pairs gave students additional insight in solving each problem.

physics.ed-ph↗

arXiv2016

Multiple-choice test of energy and momentum concepts

We investigate student understanding of energy and momentum concepts at the level of introductory physics by designing and administering a 25-item multiple choice test and conducting individual interviews. We find that most students have difficulty in qualitatively interpreting basic principles related to energy and momentum and in applying them in physical situations.

physics.ed-ph↗

arXiv2016

Categorization of problems to assess and improve proficiency as teachers and learners

We describe how graduate students categorize introductory mechanics problems based on the similarity of their solutions. Graduate students were asked at the end of a teaching assistant training class to categorize problems from their own perspective and from the perspective of typical introductory physics students whom they were teaching. We compare their categorizations with the categorizations by introductory physics students and physics faculty who categorized the same problems. The utility of categorization as a tool for teaching assistant training and faculty development workshops is discussed.

physics.ed-ph↗

arXiv2016

Increasing interest and awareness about teaching in science undergraduates

We discuss the development, implementation, and assessment of a course for science undergraduates designed to help them develop an awareness and a deeper appreciation of the intellectual demands of physics teaching. The course focused on increasing student enthusiasm and confidence in teaching by providing well supported teaching opportunities and exposure to physics education research. The course assessment methods include 1) pre/post-tests measures of attitude and expectations about science teaching, 2) self and peer evaluation of student teaching, 3) content-based pre/post-tests given to students who received instruction from the student teachers, and 4) audio-taped focus group discussions in the absence of the instructor and TA to evaluate student perspective on different aspects of the course and its impact.

physics.ed-ph↗

arXiv2016

Improving Student Understanding of Coulomb's Law and Gauss's Law

We discuss the development and evaluation of five research-based tutorials on Coulomb's law, superposition, symmetry and Gauss's Law to help students in the calculus-based introductory physics courses learn these concepts. We discuss the performance of students on the pre-/post-tests given before and after the tutorials in three calculus-based introductory physics courses. We also discuss the performance of students who used the tutorials and those who did not use it on a multiple-choice test which employs concepts covered in the tutorials.

physics.ed-ph↗

arXiv2016

Coupling Conceptual and Quantitative Problems to Develop Expertise in Introductory Physics Students

We discuss the effect of administering conceptual and quantitative isomorphic problem pairs (CQIPP) back to back vs. asking students to solve only one of the problems in the CQIPP in introductory physics courses. Students who answered both questions in a CQIPP often performed better on the conceptual questions than those who answered the corresponding conceptual questions only. Although students often took advantage of the quantitative counterpart to answer a conceptual question of a CQIPP correctly, when only given the conceptual question, students seldom tried to convert it into a quantitative question, solve it and then reason about the solution conceptually. Even in individual interviews, when students who were only given conceptual questions had difficulty and the interviewer explicitly encouraged them to convert the conceptual question into the corresponding quantitative problem by choosing appropriate variables, a majority of students were reluctant and preferred to guess the answer to the conceptual question based upon their gut feeling.

physics.ed-ph↗

arXiv2016

Problem Solving and Learning

One finding of cognitive research is that people do not automatically acquire usable knowledge by spending lots of time on task. Because students' knowledge hierarchy is more fragmented, "knowledge chunks" are smaller than those of experts. The limited capacity of short term memory makes the cognitive load high during problem solving tasks, leaving few cognitive resources available for metacognition. The abstract nature of the laws of physics and the chain of reasoning required to draw meaningful inferences makes these issues critical. In order to help students, it is crucial to consider the difficulty of a problem from the perspective of students. We are developing and evaluating interactive problem-solving tutorials to help students in the introductory physics courses learn effective problem-solving strategies while solidifying physics concepts. The self-paced tutorials can provide guidance and support for a variety of problem solving techniques, and opportunity for knowledge and skill acquisition.

physics.ed-ph↗

arXiv2016

Assessing Expertise in Quantum Mechanics using Categorization Task

We discuss the categorization of 20 quantum mechanics problems by 6 physics professors and 22 undergraduate students from two honors-level quantum mechanics courses. Professors and students were asked to categorize the problems based upon similarity of solution. We also had individual discussions with professors who categorized the problems. Faculty members' categorizations were overall rated better than those of students by three faculty members who evaluated all of the categorizations. But the categories created by faculty members were more diverse compared to the uniformity of the categories they created when asked to categorize introductory mechanics problems.

physics.ed-ph↗

arXiv2016

Students' Understanding of Stern Gerlach Experiment

The Stern Gerlach experiment has played a central role in the discovery of spin angular momentum and it has also played a pivotal role in elucidating foundational issues in quantum mechanics. Here, we discuss investigation of students' difficulties related to the Stern Gerlach experiment by giving written tests and interviewing advanced undergraduate and graduate students in quantum mechanics. We also discuss preliminary data that suggest that the Quantum Interactive Learning Tutorial (QuILT) related to the Stern Gerlach experiment is helpful in improving students' understanding of these concepts.

physics.ed-ph↗

arXiv2016

Rethinking Tools for Training Teaching Assistants

The ability to categorize problems is a measure of expertise in a domain. In order to help students learn effectively, instructors and teaching assistants (TAs) should have pedagogical content knowledge. They must be aware of the prior knowledge of students they are teaching, consider the difficulty of the problems from students' perspective and design instruction that builds on what students already know. Here, we discuss the response of graduate students enrolled in a TA training course to categorization tasks in which they were asked to group problems based upon similarity of solution first from their own perspective, and later from the perspective of introductory physics students. Many graduate students performed an expert-like categorization of introductory physics problems. However, when asked to categorize the same problems from the perspective of introductory students, many graduate students expressed dismay, claiming that the task was impossible, pointless and had no relevance to their TA duties. We will discuss how categorization can be a useful tool for scaffolding and improving pedagogical content knowledge of teaching assistants and instructors.

physics.ed-ph↗

arXiv2016

Using Analogies to Learn Introductory Physics

Identifying the relevant physics principles is a central component of problem solving. A major goal of most introductory physics courses is to help students discern the deep similarities between problems based upon the physics principles so that they can transfer what they learned by solving one problem to solve another problem which involves the same principle. We conducted an investigation in which 251 calculus- and algebra-based introductory physics students were asked explicitly in the recitation quiz to learn from a solved problem and then solve another problem that has different surface features but the same underlying physics principles. We find that many students were able to discern the deep similarities between the problems. When the solved problem was provided, students were likely to invoke the correct principles; however, more scaffolding is needed to help students apply these principles correctly.

physics.ed-ph↗