Peter S. Shaffer

Research as a guide for curriculum development: An example from introductory electricity. Part I: Investigation of student understanding

A method of and apparatus for determining the quantity of phenols in an aqueous solution after treating the solution to remove interfering impurities therefrom. The treated aqueous solution is electrolytically alternately converted so as to be either acidic or basic with preselected and controlled pH values. These acidic and basic solutions are subjected to ultraviolet radiation at a preselected wavelength so that the amount of radiation passing therethrough at the preselected pH values can be measured. The measured amounts of ultraviolet radiation passing through the acidic and basic solutions are compared to determine the concentration of phenols in the aqueous solution.

Research as a guide for curriculum development: An example from introductory electricity. Part II: Design of instructional strategies

This is the second of two closely related articles that together describe how results from research can be used as a guide for curriculum development. The first article shows how the investigation of student understanding of electric circuits by the Physics Education Group has contributed to the building of a research base. This second article describes how the group has drawn on this resource both in developing a curriculum for laboratory‐based instruction and in adapting this curriculum to fit the constraints of a traditional introductory course. Also discussed is how, in turn, development and implementation of the curriculum have enriched the research base.

Preparing teachers to teach physics and physical science by inquiry

In physics, neither courses for majors nor for non-majors provide the kind of preparation required for teaching physics or physical science by inquiry. Science methods courses cannot help teachers develop the depth of understanding needed for this type of teaching. Since appropriate preparation is not available through the standard curriculum, a practical alternative is to offer special physics courses for teachers.

Research as a guide for teaching introductory mechanics: An illustration in the context of the Atwood’s machine

A problem on the Atwood’s machine is often introduced early in the teaching of dynamics to demonstrate the application of Newton’s laws to the motion of a compound system. In a series of preliminary studies, student understanding of the Atwood’s machine was examined after this topic had been covered in a typical calculus‐based course. Analysis of the data revealed that many students had serious difficulties with the acceleration, the internal and external forces, and the role of the string. The present study was undertaken to obtain more detailed information about the nature and prevalence of these difficulties and thus provide a sound basis for the design of more effective instruction. The context for the investigation is a group of related problems involving less complicated compound systems. Specific examples illustrate how this research, which was conducted primarily in a classroom setting, has served as a guide in the development of tutorial materials to supplement the lectures and textbook in a stan...

An investigation of student understanding of single-slit diffraction and double-slit interference

Results from an investigation of student understanding of physical optics indicate that university students who have studied this topic at the introductory level and beyond often cannot account for the pattern produced on a screen when light is incident on a single or double slit. Many do not know whether to apply geometrical or physical optics to a given situation and may inappropriately combine elements of both. Some specific difficulties that were identified for single and double slits proved to be sufficiently serious to preclude students from acquiring even a qualitative understanding of the wave model for light. In addition, we found that students in advanced courses often had mistaken beliefs about photons, which they incorporated into their interpretation of the wave model for matter. A major objective of this investigation was to build a research base for the design of a curriculum to help students develop a functional understanding of introductory optics.

Student understanding of the ideal gas law, Part I: A macroscopic perspective

Our findings from a long-term investigation indicate that many students cannot properly interpret or apply the ideal gas law after instruction in introductory physics and chemistry as well as more advanced courses. The emphasis in this paper is on the concepts of pressure, volume, and temperature at the macroscopic level. We describe some serious conceptual and reasoning difficulties that we have identified. Results from our research were applied in the design of a curriculum that has helped improve student understanding of the ideal gas law.

Development and assessment of a research-based tutorial on light and shadow

This article describes an investigation of student understanding of geometrical optics and illustrates the use of research as a basis for the development of curriculum. Evidence is presented that university students who have studied physics at the introductory level and beyond often cannot apply basic concepts from geometrical optics to account for the pattern produced on a screen when an aperture or obstacle is placed between a light source and the screen. Identification and analysis of student difficulties guided the initial design of a tutorial to supplement instruction in a typical calculus-based or algebra-based course. Development of a laboratory-based, inquiry-oriented curriculum for precollege teachers took place concurrently. Ongoing assessment was an integral part of the curriculum development process. The instructional materials that evolved from this iterative cycle have proved to be effective with the target populations.

Student understanding of time in special relativity: Simultaneity and reference frames

This article reports on an investigation of student understanding of the concept of time in special relativity. A series of research tasks are discussed that illustrate, step-by-step, how student reasoning of fundamental concepts of relativity was probed. The results indicate that after standard instruction students at all academic levels have serious difficulties with the relativity of simultaneity and with the role of observers in inertial reference frames. Evidence is presented that suggests many students construct a conceptual framework in which the ideas of absolute simultaneity and the relativity of simultaneity harmoniously co-exist.

Addressing student difficulties in applying a wave model to the interference and diffraction of light

This article illustrates the use of research as a basis for the development of curriculum on physical optics. Evidence is presented that university students who have studied physics at the introductory level and beyond often do not have a functional understanding of the wave model for light. Identification and analysis of student difficulties guided the design of a set of tutorials to supplement instruction in a standard calculus-based or algebra-based course. Ongoing assessment was an integral part of the curriculum development process. The instructional materials that resulted have proved to be effective at helping students construct and apply a basic wave model for light.

A research-based approach to improving student understanding of the vector nature of kinematical concepts

In this paper we describe a long-term, large-scale investigation of the ability of university students to treat velocity and acceleration as vectors in one and two dimensions. Some serious conceptual and reasoning difficulties identified among introductory students also were common among pre-college teachers and physics graduate students. Insights gained from this research guided the development of instructional materials that help improve student learning at the introductory level and beyond. The results have strong implications for the teaching of undergraduate physics, the professional development of teachers, and the preparation of teaching assistants.