Classroom Polling and Peer Instruction

Posted May 19, 2015

By Jeffrey R. Stowell

It takes a measure of humility for teachers to recognize that they are not the source of all knowledge that flows into the classroom. Students can be a valuable resource to teach their peers despite their inexperience as formal teachers. By allowing students to teach one another, students have an opportunity to share their learning as well as ascertain their own limitations in understanding. As a teacher, I have often told my students that a good measure of their understanding is their ability to teach a concept to another person.

According to Crouch and Mazur (2001), “Peer Instruction engages students during class through activities that require each student to apply the core concepts being presented, and then to explain those concepts to their fellow students.” In a typical peer instruction model, students first generate their own responses to questions posed by the instructor. Then, students share their answer with another student, or a small group of students, providing reasoning for their answer. As they do so, the additional perspective and reasoning from peer instruction allows them to eliminate incorrect answers and generally move in the direction of the correct answer. Peer instruction, in conjunction with other pedagogical techniques to better prepare students for class, significantly improved grades on a standardized Physics test (Crouch and Mazur, 2001).

Why does peer instruction work? Smith et al. (2009), in an undergraduate genetics course that used hand-held keypads (“clickers”) for classroom polling in conjunction with peer instruction, found that repolling students after a brief discussion with one another improved the chances of getting the same question (and, more importantly, a subsequent conceptually-similar question) correct, even when no one in the initial discussion group knew the correct answer. The improvement was most pronounced with difficult, rather than easy questions. Although performance on questions of all difficulty levels improved by about 16% after the initial round of peer discussion, performance on the most difficult questions improved an additional 22% (for a total of 38%) on the subsequent conceptually-similar question answered alone. Based on open-ended feedback from students, the authors suggested that it’s not necessary for a member of a peer discussion group to know the correct answer. Rather, through elimination of incorrect answers and deeper conceptual understanding that emerges from the debate, students are learning!

Instructors who are interested in using peer instruction with classroom polling have a full range of possibilities for collecting student’s responses in class.

  • Low-tech: One option is to simply ask students to raise their hands to indicate which answer they think is correct. Unfortunately, when students are unsure of their answer, they may not respond. Or, if they do respond, their choice of correct answers is likely to be influenced by social conformity when a sufficient number of other students’ hands are raised. Once a critical number of hands have gone up, you can witness the “lemming effect,” although the outcome is not as fatal. A few other simple methods exist including using color-coded index cards (e.g., red for answer 1, blue for 2, etc.) and having cards with difference answer choices written in large font (how good is your vision?).
  • High-tech: For instructors who wish to use technology to gather student responses, a number of options are available. Traditionally, clickers have been used in the classroom which students use to indicate their response by pressing a button that corresponds to their answer. The wireless radio signal sent from the clicker is received by a USB device on the instructor’s computer (gone are the days of infrared signals when you had to aim the clicker right at the receiver, yay!). The computer tallies students’ responses and displays them in a histogram chart. A number of integrated clicker solutions are available including TurningPoint™ and iClicker™. A variety of mobile device apps are also now available, turning students’ smartphones into mobile clickers. Some of these apps are free (e.g., Socrative), while others require a subscription (e.g., TurningPoint). Responses obtained through a mobile device are comparable to those obtained using a clicker, but because of the added degrees of freedom for technical errors, using a mobile device may result in a greater number of missing responses.

Regardless of the polling method, the suspense of waiting for the class’s responses is exciting, and the occasional large discrepancy between how well I thought I taught a concept and the students’ actual understanding can be surprising. If a large majority of the class (>75% or so) is correct after the initial question, there is not much to be gained by introducing peer discussion and the instructor may simply confirm the correct answer and proceed. However, after posing a question that results in fewer students getting it correct (50-60%), peer discussion can promote significant gains in student learning. Further explanation of the correct answer by the instructor may be necessary, depending on the results from the second poll.

Implementing peer instruction has some costs:

  • An additional amount of time is required for discussion, which comes at the expense of covering more material. However, given the gains in learning through peer instruction, this should not deter instructors from implementing it gradually into their lectures.
  • The costs of technology can be a burden to students and institutions. Yet, the arrival of free polling apps for smartphones (which are nearly universal among college-age adults) can make the transition into the digital polling relatively smooth.

Regularly assessing student learning in the classroom and providing the opportunity for students to teach one another blends personal responsibility for learning with the benefits of cooperative peer instruction. The process engages students in the classroom and, when used in conjunction with classroom polling, reveals accurate assessment of student learning and allows instructors to meet the real-time needs of students.


Crouch, C. H., & Mazur, E. (2001). Peer instruction: Ten years of experience and results. American Journal of Physics, 69, 970.

Smith, M. K., Wood, W. B., Adams, W. K., Wieman, C., Knight, J. K., Guild, N., & Su, T. T. (2009). Why peer discussion improves student performance on in-class concept questions. Science, 323(5910), 122–124. doi:10.1126/science.1165919

Stowell, J. R. (2015). Use of clickers vs. mobile devices for classroom polling. Computers & Education, 82, 329–334. doi:10.1016/j.compedu.2014.12.008

Stowell, J. R., & Nelson, J. M. (2007). Benefits of electronic audience response systems on student participation, learning, and emotion. Teaching of Psychology, 34(4), 253–258. doi:10.1080/00986280701700391

[Dr. Jeffrey Stowell is a Professor and the Assistant Chair of the Department of Psychology at Eastern Illinois University in Charleston, IL, where he teaches courses related to his specialty in Biological Psychology. His research interests are in the scholarship of teaching and learning and the role of technology in education.]