This report summarizes the complex research literature on quantitative methods for assessing how impacts of educational interventions on instructional practices and student learning differ across students, educators, and schools. It also provides technical guidance about the use and interpretation of these methods. The research topics addressed…

Using meta-analysis, randomized experiments in education that either clearly did or clearly did not experience student attrition were examined for the baseline comparability of groups. Results from 35 studies suggested that after attrition, the observed measures of baseline comparability of groups did not differ more than would be expected given…

A review and meta-analysis were made of placebo control groups in educational experiments. In all, 125 studies were clustered into procedures that included (1) explicit manipulation of attentional elements; (2) explicit description of the placebo activity plus implied reference to attention; and (3) exclusive reference to the activity. (SLD)

A review of 208 studies of children with learning disabilities (LD) published in 10 major journals between 1988 and 1990 examined the extent to which recommendations concerning research design and reporting made in 1980 and 1984 have been implemented. The review found continuing problems, including imprecise subject descriptions, heterogeneous…

Conducting observational research in a cross-cultural context invokes a unique set of difficulties. This paper describes sources of bias and threats to validity that are specific to cross-cultural research. It describes problems of cross-cultural research designs for descriptive studies, comparative research, and experimental research and outlines…