ERIC Number: EJ314653
Record Type: CIJE
Publication Date: 1984
Reference Count: 0
Estimation of Effect Size Under Nonrandom Sampling: The Effects of Censoring Studies Yielding Statistically Insignificant Mean Differences.
Hedges, Larry V.
Journal of Educational Statistics, v9 n1 p61-85 Spr 1984
If the quantitative result of a study is observed only when the mean difference is statistically significant, the observed mean difference, variance, and effect size are biased estimators of corresponding population parameters. The exact distribution of sample effect size and the maximum likelihood estimator of effect size are derived. (Author/BW)
Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Authoring Institution: N/A
Note: Research supported by the Spencer Foundation.