The Role of Comparative Processes in Shaping the Effects of Between-Class Ability Grouping on Students' Math Ability Self-Concept

Many researchers have studied the effects of ability grouping on students' academic self-concept due to its critical importance for students' educational choices and trajectories. However, the available evidence is almost exclusively correlational, the results are inconsistent, and it is thus unclear how ability grouping may influence students' academic self-concept. This study applies causal inference methods to understand the mechanisms underlying the effects of math ability grouping on students' math self-concept. Using a quasi-experimental design and following students who transitioned from elementary school (Grade 6) to middle school (Grade 7) with or without ability grouping (N = 1,660, 90% White, 53% female), we investigated whether between-class math ability grouping impacts seventh graders' formation of their math self-concept through comparative processes (social and dimensional comparisons) and objective performance information. Through propensity score weighting and average marginal effect estimation, we found that high-grouped students reported lower math self-concepts than high-achieving ungrouped students, and low-grouped students reported higher math self-concepts than low-achieving ungrouped students at the end of Grade 7. Average-achieving students attending schools with a between-class grouping policy showed stronger dimensional comparison effects than their ungrouped counterparts. The effects of prior math performance on math self-concept were nonsignificant for high- and low-achieving students, regardless of their grouping status. These findings advance our understanding of how pervasive school practices, such as ability grouping, shape students' self-relevant motivational beliefs.