Peer Instruction (Mazur, 1997) has long been recognized as an effective way for students to learn in the physics classroom since its inception in the 1990s. PI takes the form of asking a series of questions, followed by student discussion, and frequently follows up with asking the same question again to learn what percentage of the class changed their initial answer. The PI methodology is therefore student-centered in nature and the percentage of correct answers to a question increases on nearly every occasion that this technique is administered. Following this result, numerous disciplines have shown the effectiveness of peer instruction in their classrooms, from computer science to chemistry.
One study in biology has examined why peer discussion is important for answering conceptual questions during class (Smith, et al. 2009). A recent study by Miller, et al. goes one step further to address this question by tracking individual students' responses over the course of an introductory, calculus-based physics class. In this study, the authors were interested in the students who answered the questions incorrectly, then in the second round switched their answer to either the correct answer or another wrong answer. They found that students on average switched their answer 44% of the time, and of the switched responses, 73% of these switched from incorrect to correct responses.
The authors added another layer to this study by having the students answer questions about their confidence in their ability to do physics- or science-related things. The term for this is self-efficacy, and sample statements from the survey include, "I usually don’t worry about my ability to solve physics problems" and "I can communicate science effectively". The authors found that students who had lower pre-course self-efficacy were more likely to change their conceptual questions answers to an incorrect answer. The authors also observed that all students tended to switch their answers to a wrong answer when the questions increased in difficulty.
These results suggest that there are two areas you can focus on as an instructor to help improve student performance during Peer Instruction. One area involves scaffolding questions as they increase in difficulty, that is, giving students guidance on how to answer questions as they become more challenging. The second area is about increasing students' self-efficacy throughout the course. Ideally, as self-efficacy increases, so will students’ ability to answer conceptual questions. Taking both of these approaches would also result in an increase in student learning in the course.
Gloriana Trujillo, Ph.D. is Associate Director for STEM Learning in VPTL, the Office of the Vice Provost for Teaching and Learning.
Mazur, Eric. Peer instruction. Upper Saddle River, NJ: Prentice Hall, 1997.
Miller, Kelly, et al. "Response switching and self-efficacy in Peer Instruction classrooms." Physical Review Special Topics-Physics Education Research 11.1 (2015): 010104.
Smith, Michelle K., et al. "Why peer discussion improves student performance on in-class concept questions." Science 323.5910 (2009): 122-124.