This review introduces classical item response theory (IRT) models as well as more
contemporary extensions to the case of multilevel, multidimensional, and mixtures of …

Now in its 6th edition, the authoritative textbook Applied Multivariate Statistics for the Social
Sciences, continues to provide advanced students with a practical and conceptual …

This article discusses the nonuse, misuse, and proper use of pilot studies in experimental
evaluation research. The authors first show that there is little theoretical, practical, or …

While a great deal of thought, planning, and money goes into the design of multisite
randomized control trials (RCTs) that are used to evaluate the effectiveness of interventions …

Outcome-reporting bias occurs when primary studies do not include information about all
outcomes measured in a study. When studies omit findings on important measures, efforts to …

A substantial number of randomized trials of educational interventions that have been
conducted over the past two decades have produced null results, with either no impact or an …

For the cluster randomized trial, the treatment, implemented at the cluster level, may be
hypothesized to impact a final outcome of interest via a mediating variable, with the mediator …

Randomized experiments are often seen as the “gold standard” for causal research. Despite
the fact that experiments use random assignment to treatment conditions, units are seldom …

To plan group-randomized trials where treatment conditions are assigned to schools,
researchers need design parameters that provide information about between-school …

This article examines the statistical precision of cluster randomized trials (CRTs) funded by
the Institute of Education Sciences (IES). Specifically, it compares the total number of …