This paper is directed to researchers who conduct and report education intervention studies. Its purpose is to stimulate and guide them to go a step beyond reporting the statistics that emerge from their analysis of the differences between experimental groups on the respective outcome variables. With what is often very minimal additional effort,…

This paper includes a nontechnical description of methods for calculating effect sizes in intellectual and developmental disability studies. Different hypothetical studies are used to illustrate how null hypothesis significance testing (NHST) and effect size findings can result in quite different outcomes and therefore conflicting results. Whereas…

The Penn Manor CRT/Curriculum Articulation Project was designed to study the impact of the implementation of four specific interventions on the achievement of elementary school students in mathematics and language arts. The interventions were as follows: (1) classroom teachers were given individual curriculum skill objectives for their grade…