Related Experiment Video
Updated: May 30, 2026

Problem-Solving Before Instruction (PS-I): A Protocol for Assessment and Intervention in Students with Different Abilities
Published on: September 11, 2021
Low effect sizes of evidence-based programs in school settings
Joelle D Powers1, Natasha K Bowen, Kristina C Webber
1School of Social Work, The University of North Carolina at Chapel Hill, USA. jdpowers@email.unc.edu
Abstract:
School practitioners working from an evidence-based practice framework are expected to implement interventions that are effective with students. In the current study, the authors explore the feasibility of that expectation in light of the availability of critical effect size information necessary for making informed intervention decisions. Effect sizes for 51 school-based programs endorsed as effective by authoritative sources were reviewed. Effect size analyses reveal that the programs were not, on average, highly effective. Difficulties finding effect size information and programs with high effect sizes are discussed. Recent advances in evidence-based programs and suggestions for increasing the feasibility of evidence-based programs in schools are offered.
Related Concept Videos
One-Way ANOVA: Equal Sample Sizes
Different sample means can result in different values for the variance estimate: variance between samples. This is because the variance between samples is calculated as the product of the sample size and the variance between the...
Regression Toward the Mean
Statistical Significance
Bias in Epidemiological Studies
Group Design
Cause and Effect