Instructors who implemented PI in this sense were initially polling the class in order to ascertain whether students were learning in lecture-style classes; the "turn to your neighbor" aspect was a follow-on aimed at overcoming student confusion in specific cases. Thus the research focuses on learning gains, both after a given poll/discussion/re-poll episode and for entire courses. Studies in STEM fields show that PI can greatly increase student comprehension of conceptual material even when the questions asked are not themselves purely conceptual. While it is most prevalent in STEM fields, PI has been implemented in other fields [for example (4), and see also (5) and (6)].
Even though the technique has come to be associated with specific tech (clickers and more sophisticated response systems), the main result from the research is that it is the students' interactive struggling with concepts that produces learning gains, which are likely to occur even when two students discussing together both initially had an incorrect response. A low-tech implemention involves simply provide students with a sheet of paper with each letter "A B C D" (representing response choices) in a different corner of the page, in different colors, so they can fold it to show only one letter and so vote with it for easy, if appproximate visual collation by the instructor. For gathering data for research however a more robust system (clickers, Learning Catalytics, etc.) would be required.
 Crouch, C. H.; Mazur, E. Peer Instruction: Ten years of experience and results. Am. J. Phys. 2001, 69, 970.
 Fagen, A. P.; Crouch, C. H.; Mazur, E. Peer instruction: Results from a range of classrooms. The Physics Teacher 2002, 40, 206.
 Miller, R. L.; Santana-Vega, E.; Terrell, M. S. Can good questions and peer discussion improve calculus instruction? Problems, Resources,
and Issues in Mathematics Undergraduate Studies 2006, 16, 193-203.
 Butchart, S.; Handfield, T.; Restall, G., 2009. "Using Peer Instruction to teach Philosophy, Logic and Critical Thinking". Teaching Philosophy, 32:1, 1-40.
 Turn to Your Neighbor ("Official PI blog") blog.peerinstruction.net
 Agile Learning blog derekbruff.org/teachingwithcrs
 for example, learningcatalytics.com
 Smith, M. K.; Wood, W. B.; Adams, W. K.; Wieman, C.; Knight, J. K.; Guild, N.; Su, T. T. Why peer discussion improves student performance on in-class concept questions. Science 2009, 323, 122-124.
- Bruff, Derek, Teaching with classroom response systems: creating active learning environments. Jossey-Bass 2009, ISBN 9780470288931
- "Teaching with Personal Response Systems", Derek Bok Center. bokcenter.harvard.edu/?k1985&pageid=icb.page494961