手法を比較

	What Works Clearinghouse Standards	Effect Size in Education Research
分野	Education	Education
系統	Process / pipeline	Process / pipeline
提唱年	2022	1988
提唱者	Institute of Education Sciences (IES), U.S. Department of Education	Statistical methodology (Cohen; Glass; Hedges & Olkin) applied in education
種類	Standards and procedures for assessing the causal credibility of education studies	Standardized index of the magnitude of an effect or difference
原典	What Works Clearinghouse. (2022). What Works Clearinghouse Procedures and Standards Handbook, Version 5.0. Institute of Education Sciences, U.S. Department of Education.	Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences (2nd ed.). Lawrence Erlbaum Associates. ISBN: 9780805802832
別名	WWC Standards, WWC Evidence Standards, What Works Clearinghouse Review, WWC Study Rating	Educational Effect Size, Standardized Mean Difference in Education, Hedges' g in Education, Effect Size Reporting
関連	3	2
概要	The What Works Clearinghouse (WWC) standards are the protocol the U.S. Institute of Education Sciences uses to judge how much confidence an education study's findings deserve as causal evidence. They specify which designs can support causal claims, how to screen for threats such as attrition and confounding, and how to rate each study — Meets Standards Without Reservations, With Reservations, or Does Not Meet Standards — before synthesizing the body of evidence. The standards are a cornerstone of evidence-based education policy in the United States.	An effect size is a standardized, scale-free measure of the magnitude of a difference or relationship — how big an effect is, not just whether it is statistically significant. In education research it is the common currency for reporting intervention impacts and for combining studies in meta-analysis, with the standardized mean difference (Cohen's d, or its bias-corrected form Hedges' g) the most familiar. Effect sizes let researchers compare effects across studies, outcomes, and scales, and translate statistical results into terms practitioners can weigh.