Two steps forward, one step back:Effect size reporting in gifted education research from 1995–2000

The APA Task Force on Statistical Inference recently recommended reporting effect sizes alongside results of statistical significance tests. The purpose of this article is to investigate effect size usage in gifted education research and to follow up on a similar investigation published by Plucker (1997). A content analysis of effect size reporting was conducted of articles published in the Journal for the Education of the Gifted, Roeper Review, and Gifted Child Quarterly from 1995–2000. Results of the present study were similar to the findings of Plucker (1997): No statistical difference in reporting was found across journals or across years, and a moderate difference was found between effect size reporting in univariate versus multivariate statistics. The benefits to gifted education research of understanding the relationship among sample size, effect size, and statistical power are discussed.