The Evidence on Teaching

Mathematics Instruction for Students with Learning Disabilities: A Meta-Analysis of Instructional Components

Gersten, R., Chard, D. J., Jayanthi, M., Baker, S. K., Morphy, P., & Flojo, J. · 2009

grade Cmeta-analysisindependentmixednumbers spot-checked
Sample
42 intervention studies (RCT + QED)
Population
K-12 students with learning disabilities.
Design
Components coded; primary studies small with researcher-designed treatment-aligned measures.
Key findings
The most-cited quantification of explicit instruction for struggling math learners (g=1.22). Direction is the field's most replicated finding; magnitude is aligned-measure inflated — read against Gersten 2015's standardized +0.34 benchmark.
Genetic confound
Experimental base; LD samples are ability-selected — teachable-skill gains in low-performing populations.
Replication notes
Direction robust across independent metas + WWC 2021; the headline magnitude has never been reproduced on independent standardized outcomes (expect ~half).
DOI / URL
10.3102/0034654309334431

Effects

OutcomeMetricValueMeasureTimingVsHorizonClass
Explicit instruction componentg1.22 (range of study effects 0.08-2.15)researcher-designedend-of-treatmentunclearend-of-treatmentdomain-skill
Teaching heuristicsg1.56researcher-designedend-of-treatmentunclearend-of-treatmentdomain-skill

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