Textbook Presentations on Supplemental Hypothesis Testing Activities, Nonnormality, and the Concept of Mediation

Abstract

This study reviewed 12 introductory statistics textbooks for the behavioral sciences published since 1998. The intent was to identify how well selected recent developments in the statistics field were incorporated into these texts. Textbooks generally included concepts such as effect size, confidence intervals, power and a priori sample size determination, and statistical assumptions. However, no text presented a design and analysis approach that integrated all of these data analysis activities into the standard hypothesis testing procedures. Second, few texts appeared to incorporate recent research regarding the effects of nonnormality on analysis results. In addition, no text illustrated tests involving newly developed robust estimators or modern rank-based techniques even though such procedures can effectively handle problems associated with nonnormality that frequently arise in behavioral data. Finally, few authors of the basic statistics textbooks, as well as authors of some highly respected analysis of variance texts, advanced examining hypotheses involving mediators as a valued research goal.