Statistical approaches to assess how prevention and intervention programs achieve their effects are described and illustrated through the evaluation of a health promotion program to reduce dietary cholesterol and a school-based drug prevention program. Analyses require the measurement of intervening or mediating variables to represent the…

A technique to estimate variances of weighted estimates in program evaluation is discussed. BRR estimates of variance are constructed from orthogonally weighted subsamples and can provide better estimates from complex samples than can other methods. Use of BRR is illustrated in a government evaluation of a food service program. (SLD)

Statistical methods for program evaluation with nonexperimental data are reviewed with emphasis on circumstances in which nonexperimental data are valid. Three solutions are proposed for problems of selection bias, and implications for evaluation design and data collection and analysis are discussed. (SLD)

Estimates of program effects from a compensatory preschool intervention were investigated using econometric simultaneous modeling, latent variable structured modeling, and ordinary least squares regression. Data for 806 black children indicated that different quasi-experimental estimation methods that attempt to control for selection bias can…