Peer tutoring and mathematics in secondary education: literature review, effect sizes, moderators, and implications for practice

A literature review was undertaken to compile all data on peer tutoring in secondary education (7^th to 12^th grade) mathematics from existing articles. Data from 42 independent studies were included in this research. All data regarding participants' roles (fixed vs. reciprocal), participants' ages (same-age vs. cross-age), the methodological approach taken (quantitative or qualitative), the type of design for those studies that involved a quantitative approach, the variables analyzed, and the organizational matters (number of participants, duration of the program, sessions per week, and duration of the sessions) are included in the article. The effect sizes of the 42 studies were calculated and examined. The main goal of the study was to determine those variables that were moderators of effect size, that is, the variables that significantly influenced students' academic achievement outcomes. Inferential statistical analyses (Student's t-test and ANOVAs) were carried out for the variables. Of the 42 studies examined, 88% showed positive effect sizes with the means being close to medium (Cohen's d = 0.38). Conclusions suggest the implementation of same-age over cross-age tutoring, during programs of fewer than 8 weeks, in sessions of less than 30 minutes is optimal for improving students' academic outcomes. Inclusion of control groups in similar future studies is recommended so effect sizes are not overestimated.