A recent meta-analysis examines whether test preparation improves performance in large-scale educational tests. Although schools, commercial institutions, and students invest heavily in preparation courses and materials, existing studies have reported inconsistent effects. Earlier reviews were also concentrated on US college admission and cognitive ability tests and often relied on evidence published before 2000. This study therefore estimates the overall effect of test preparation and examines how it varies across intervention, test, student, and research-design characteristics.
The authors synthesized 28 experimental and quasi-experimental studies, including 92 effect sizes and 16,741 participants across primary, secondary, and tertiary education. The studies covered college admission tests, English proficiency tests, and other large-scale assessments. A hierarchical random-effects model with robust variance estimation was used, while moderator analyses examined intervention breadth, strategy and material use, test characteristics, previous test experience, and study design.
Test preparation produced a significant positive overall effect on test performance (g=.26, 95% CI [.10,.42], p<.001), but heterogeneity was high (I^2=82.44%). Test-specific and narrowly focused interventions were more effective (g=.33) and (g=.32) than broad programs aimed at general knowledge or transferable skills (g=-.04). Interventions teaching test-taking strategies also showed stronger effects (g=.35) than those without such instruction (g=.05). Students with previous testing experience benefited substantially more (g=.69) than those without it (g=.06). However, preparation effects did not transfer significantly to other tests in the same domain (g=.06, p=.502).
Taken together, the findings suggest that test preparation can improve large-scale test scores, but its effectiveness mainly reflects alignment with the target test rather than broader learning gains. The limited transfer effect raises concerns about whether score improvement represents genuine development in the abilities being assessed. Future research should use stronger experimental designs, report intervention processes more clearly, and distinguish test-score gains from transferable learning.
Source (Open Access): Hao, Z., Baird, J. A., Masri, Y. E., & Double, K. (2025). The impact of test preparation on performance of large-scale educational tests: A meta-analysis of experimental studies. Review of Educational Research, 00346543251360775.