Learning by teaching is one of the most prevalent contemporary educational practices, but we still don't understand when it works, and why.
Learning by teaching is one of the most prevalent contemporary educational practices, including peer-assisted learning (Healey, Flint, & Harrington, 2014; Stoddard, Rieser, Andersson, & Friman, 2012), peer tutoring (King, 1998), problem-based learning (Leary, Walker, Shelton, & Fitt, 2013), cooperative classrooms (Slavin, 1995), on-line learning (Jopling, 2012), and computer-supported collaborative learning (Dillenbourg, Baker, Blaye, & O'Malley, 1995). While the practices of peer teaching and tutoring vary widely (Topping, 2005), there is reliable and representative empirical evidence for benefits to both tutees (or pupils), and tutors. For instance, a meta-analysis of 81 peer tutoring studies in elementary school (Rohrbeck, Ginsburg-Block, Fantuzzo, & Miller, 2003) found a positive effect size of 0.33 for peer tutoring compared to control groups. In another widely cited meta-analysis, coving 65 studies, the effect size for pupils (tutees) was 0.4, and the learning gains for tutors was 0.38 (Cohen, Kulik, & Kulik, 1982). A more recent review (Roscoe & Chi, 2007) estimates the average tutor effect size to be around 0.35, combining tutor and pupil learning.