Effect of lecture instruction on student performance on qualitative questions

Abstract

The impact of lecture instruction on student conceptual understanding in physics has been the subject of research for several decades. Most studies have reported disappointingly small improvements in student performance on conceptual questions despite direct instruction on the relevant topics. These results have spurred a number of attempts to improve learning in physics courses through new curricula and instructional techniques. This paper contributes to the research base through a retrospective analysis of 20 randomly selected qualitative questions on topics in kinematics, dynamics, electrostatics, waves, and physical optics that have been given in introductory calculus-based physics at the University of Washington over a period of 15 years. In some classes, questions were administered after relevant lecture instruction had been completed; in others, it had yet to begin. Simple statistical tests indicate that the average performance of the "after lecture" classes was significantly better than that of the "before lecture" classes for 11 questions, significantly worse for two questions, and indistinguishable for the remaining seven. However, the classes had not been randomly assigned to be tested before or after lecture instruction. Multiple linear regression was therefore conducted with variables (such as class size) that could plausibly lead to systematic differences in performance and thus obscure (or artificially enhance) the effect of lecture instruction. The regression models support the results of the simple tests for all but four questions. In those cases, the effect of lecture instruction was reduced to a nonsignificant level, or increased to a significant, negative level when other variables were considered. Thus the results provide robust evidence that instruction in lecture can increase student ability to give correct answers to conceptual questions but does not necessarily do so; in some cases it can even lead to a decrease.

Testing alternative explanations for common responses to conceptual questions: An example in the context of center of mass

“…We also found that prior physics experience, even in the immediate past, is not a significant factor [9]. This phenomenon is not unique to this context-it is well known in physics that certain incorrect reasoning patterns are observed both before and after formal instruction with roughly equal frequencies [13]. In contrast to Sattizahn et al, we view this as evidence that the underlying topic-specific intuitive ideas do not interact strongly with formal instruction.…”

Curriculum development to improve student understanding of rolling motion

“…The percentage of correct answers in this case was about 25%. Since the variation we typically see on pretests from quarter to quarter and from class to class is typically about ±5% [5], this result suggests that standard lecture instruction results in something like a 10% improvement on the task.…”

University student conceptual resources for understanding energy

“…This choice was pragmatic: many of the instructors who participated in our study were reluctant to ask students to respond to questions about energy before it was discussed in their courses. Other analyses suggest that the timing of conceptual questions does not affect student performance [141]; however, this may not be true for resources-oriented work, especially given our assumption that the context will affect which resources are activated. …”