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

Abstract

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.

Understanding and affecting student reasoning about sound waves

“…Kyle was describing the dust particle moving along the path of the sinusoidal sine wave. (For similar responses in the context of physical optics, see Ambrose, Shaffer, Steinberg, & McDermott, 1999) (Linder, 1993) By 'constant path,' he was indicating movement along an p. 12 unchanging sinusoid. Later, when asked the effect of a change in the frequency, Kyle explained that K: [The dust particle] will move faster because the frequency is higher which means that, since frequency is the one that affects the dust particle, if the frequency increases, the speed of the particle should increase, also.…”

Unexpected attitudinal growth in a course combining reformed curricula

“…They are then guided to "resolve" the conflict in favor of the correct idea [40]. TIPs has been shown to be effective in improving conceptual understanding across a wide variety of topics at different levels [41][42][43][44][45][46][47] with different populations of students [48,49].…”

Investigating students’ mental models about the nature of light in different contexts

“…With the first question of the study, the aim was to determine student awareness related to scientific theories of light. In the other four questions, students were asked to explain different light-related phenomena by way of drawing, because student drawing and explanations give thorough information about their mental models and learning difficulties (Ambrose et al 1999a, Çepni and Keleş 2006, Wosilait et al 1999. The students completed the PPQ under examination conditions during a class lasting 40 min.…”

“…Another finding obtained from these studies is that students do not have a functional understanding of the wave model which they use to explain the interference and diffraction effects of light. In another study by Ambrose (1999a), it was determined that students have many difficulties concerning path difference and phase difference, which are important concepts of physical optics.…”