Showing posts with label 1998. Show all posts
Showing posts with label 1998. Show all posts

Thursday, January 15, 2009

Jolly, Zollman, Rebello & Dimitrova, Am J Phys (1998)

Visualizing motion in potential wells
P. Jolly, D. Zollman, N. Rebello & A. Dimitrova, American Journal of Physics, 66(1), p 57-63 (19998). (link to journal article)

Abstract: The concept of potential-energy diagrams is of fundamental importance in the study of quantum physics. Yet, students are rarely exposed to this powerful alternative description in introductory classes and thus have difficulty comprehending its significance when they encounter it in beginning-level quantum courses. We describe a learning unit that incorporates a sequence of computer-interfaced experiments using dynamics or air-track systems. This unit is designed to make the learning of potential-energy diagrams less abstract. Students begin by constructing the harmonic or square-well potential diagrams using either the velocity data and assuming conservation of energy or the force-displacement graph for the elastic interaction of an object constrained by springs or bouncing off springy blocks. Then, they investigate the motion of a rider magnet interacting with a configuration of field magnets and plot directly the potential-energy diagrams using a magnetic field sensor. The ease of measurement allows exploring the motion in a large variety of potential shapes in a short duration class.

Saul, PhD Dissertation (1998)

Beyond problem solving: Evaluating introductory physics courses through the hidden curriculum
J. M. Saul, Ph.D. Dissertation, E. F. Redish (advisor), (1998). (html TOC and abstract)


Abstract: A large number of innovative approaches have been developed based on Physics Education Research (PER) to address student difficulties introductory physics instruction. Yet, there are currently few widely accepted assessment methods for determining the effectiveness of these methods. This dissertation compares the effectiveness of traditional calculus-based instruction with University of Washington's Tutorials, University of Minnesota's Group Problem Solving & Problem Solving Labs, and Dickinson College's Workshop Physics. Implementation of these curricula were studied at ten undergraduate institutions. The research methods used include the Force Concept Inventory (FCI), the Maryland Physics Expectation (MPEX) survey, specially designed exam problems, and interviews with student volunteers. The MPEX survey is a new diagnostic instrument developed specifically for this study.

Instructors often have learning goals for their students that go beyond having them demonstrate mastery of physics through typical end-of-chapter problems on exams and homeworks. Because these goals are often not stated explicitly nor adequatelyreinforced through grading and testing, we refer to this kind of learning goal as part of the course's ìhidden curriculum.î In this study, we evaluate two aspects of student learning from this hidden curriculum in the introductory physics sequence: conceptual understanding and expectations (cognitive beliefs that affect how students think about and learn physics).

We find two main results. First, the exam problems and the pre/post FCI results on students conceptual understanding showed that the three research-based curricula were more effective than traditional instruction for helping students learn velocity graphs, Newtonian concepts of force and motion, harmonic oscillator motion, and interference. Second, although the distribution of students' expectations vary for different student populations, the overall distributions differ considerably from what expert physics instructors would like them to have and differ even more by the end of the first year. Only students from two of the research-based sequences showed any improvement in their expectations.

Wednesday, January 14, 2009

Wittmann, PhD Dissertation (1998)

Making sense of how students come to an understanding of physics: An example from mechanical waves
M. C. Wittmann, Ph.D. Dissertation, E. F. Redish (advisor), (1998). (html TOC and abstract)


Abstract: While physics education research (PER) has traditionally focused on introductory physics, little work has been done to organize and develop a model of how students come to make sense of the material they learn. By understanding how students build their knowledge of a specific topic, we can develop effective instructional materials. In this dissertation, I describe an investigation of student understanding of mechanical and sound waves, how we organize our findings, and how our results lead to the development of curriculum materials used in the classroom.

The physics of mechanical and sound waves at the introductory level (using small-amplitude approximation in the dispersionless system) involves fundamental concepts that are difficult for many students. These include: distinguishing between medium properties and boundary conditions, recognizing local phenomena (e.g. superposition) in extended systems, using mathematical functions of two variables, and interpreting and applying the mathematics of waves in a variety of settings. Student understanding of these topics is described in the context of wave propagation, superposition, use of mathematics, and other topics. Investigations were carried out using the common tools of PER, including free response, multiple choice, multiple-response, and semi-guided individual interview questions.

Student reasoning is described in terms of primitives generally used to simplify reasoning about complicated topics. I introduce a previously undocumented primitive, the object as point primitive. We organize student descriptions of wave physics around the the idea of patterns of associations that use common primitive elements of reasoning. We can describe students as if they make an analogy toward Newtonian particle physics. The analogy guides students toward describing a wave as if it were a point particle described by certain unique parts of the wave. A diagnostic test has been developed to probe the dynamics of student reasoning during the course of instruction.

We have replaced traditional recitation instruction with curriculum materials designed to help students come to a more complete and appropriate understanding of wave physics. We find that the research-based instructional materials are more effective than the traditional lecture setting in helping students apply appropriate reasoning elements to the physics of waves.

Monday, January 12, 2009

Redish, Saul & Steinberg, Am J Phys (1998)

Student Expectations in Introductory Physics
E. F. Redish, J. M. Saul & R. N. Steinberg, Am J Phys, 66, p 212-224 (1998). (html version)

Abstract: Students' understanding of what science is about and how it is done and their expectations as to what goes on in a science course, can play a powerful role in what they get out of introductory college physics. In this paper, we describe the Maryland Physics Expectations (MPEX) Survey; a 34-item Likert-scale (agree-disagree) survey that probes student attitudes, beliefs, and assumptions about physics. We report on the results of pre- and post-instruction delivery of this survey to 1500 students in introductory calculus-based physics at six colleges and universities. We note a large gap between the expectations of experts and novices and observe a tendency for student expectations to deteriorate rather than improve as a result of the first term of introductory calculus-based physics.