A review and meta-analysis of the effectiveness and efficiency of incremental rehearsal

Incremental rehearsal (IR) is a drill intervention that supports acquisition and fluency in basic academic skills according to prior research and a meta-analysis. The objectives of this updated and expanded systematic review and meta-analysis were to investigate the effectiveness and efficiency of IR, implementation and methodological characteristics, and whether IR can be considered an evidence-based practice. Thirty-six single case design and 24 group design studies were included, with 1,305 participants total. Within the meta-analysis, random effects models were used to estimate the effects of IR. IR resulted in large effects overall in group design and combined (group and single case design) analyses. For the group design analysis, g = 0.856, 95% CI [-0.14, 1.85], p = .09, τ² = 3.71. For the combined analysis, ES = 2.453, 95% CI [0.47, 4.44], p = .02, τ² = 10.5. IR was determined to be a practice with mixed evidence based on the findings of 10 methodologically sound studies. Additionally, IR was found to be less efficient in delayed retention than other drill interventions and similarly efficient to IR modifications. Moderator analyses did not identify statistically significant moderators of IR's effects, although these analyses were likely impacted by variability in effect sizes. (PsycInfo Database Record (c) 2026 APA, all rights reserved).