Abstract
Experiments that assign intact groups to treatment conditions are increasingly common in social research. In educational research, the groups assigned are often schools. The design of group-randomized experiments requires knowledge of the intraclass correlation structure to compute statistical power and sample sizes required to achieve adequate power. This article provides a compilation of intraclass correlation values of academic achievement and related covariate effects that could be used for planning group-randomized experiments in education. It also provides variance component information that is useful in planning experiments involving covariates. The use of these values to compute the statistical power of group-randomized experiments is illustrated.
Keywords
Intraclass correlationRandomized controlled trialCovariateRandomized experimentStatistical powerPsychologyCorrelationVariance (accounting)StatisticsSample (material)Sample size determinationEconometricsMathematicsPsychometricsMedicineEconomics
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Publication Info
- Year
- 2007
- Type
- article
- Volume
- 29
- Issue
- 1
- Pages
- 60-87
- Citations
- 791
- Access
- Closed
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Cite This
Larry V. Hedges,
E. C. Hedberg
(2007).
Intraclass Correlation Values for Planning Group-Randomized Trials in Education.
Educational Evaluation and Policy Analysis
, 29
(1)
, 60-87.
https://doi.org/10.3102/0162373707299706
Identifiers
- DOI
- 10.3102/0162373707299706