Online Intraclass Correlation Database


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For more information on how the national estimates were produced, refer to:

Hedges, L. V. & Hedberg, E. C. (2007). Intraclass correlations for planning group-randomized experiments in education. Educational Evaluation and Policy Analysis, 29, 60-87

For more information on how the state estimates were produced, refer to:

Hedges, L. V. & Hedberg, E. C. (2014). Intraclass correlations and covariate outcome correlations for planning 2 and 3 level cluster randomized experiments in education. Evaluation Review.

Acknowledgment: This research was supported in part by grants from the US Institute of Education Sciences and the National Science Foundation