Propensity score analysis is a relatively recent statistical innovation that is useful in the analysis of data from quasi-experiments. The goal of propensity score analysis is to balance two non-equivalent groups on observed covariates to get more accurate estimates of the effects of a treatment...

This study describes a method for incorporating external estimates of intraclass correlation to improve the precision for the analysis of an existing group-randomized trial. The authors use a random-effects meta-analytic approach to pool the information across studies, which takes into account...

This article builds on the previous article by Blitstein et al. (2005), which showed how external estimates of intraclass correlation can be used to improve the precision for the analysis of an existing group randomized trial. The authors extend that work to sample size estimation and power...

Background:This article revisits an article published in Evaluation Review in 2005 on sample size estimation and power analysis for group-randomized trials. With help from a careful reader, we learned of an important error in the spreadsheet used to perform the calculations and generate the...

This paper reviews four projects aimed at evaluating the technical quality of recent summative evaluations. It also helps identify some technical problems that frequently occur in evaluation research, and it outlines practical methods for solving these problems within the limits imposed by the...

President Carter proclaimed a war on fraud and error in the food stamp program as part of a more general concern with the mismanagement of social programs. He succeeded in reversing the increase in the number of households classified as receiving both too many and too few food stamps, and he...

Evaluation findings will probably make a long-term contribution to the improvement of social services and programs when they are cited in the textbooks used to train human services professionals. Although there was some variability, evaluations were nonetheless cited with reasonable frequency in...