Complex survey data are collected by means other than simple random samples. This creates two analytical issues: nonindependence and unequal selection probability. Failing to address these issues results in underestimated standard errors and biased parameter estimates. Using data from the nationally representative Head Start Family and Child…

Factors that influence the sample size necessary for longitudinal evaluations include the nature of the evaluation questions, nature of available comparison groups, consistency of the treatment in different sites, effect size, attrition rate, significance level for statistical tests, and statistical power. (Author/GDC)

This article presents a synopsis of each of seven presentations given at a conference on design and analysis in community trial studies. Papers identify problems with community trials and discuss strengths and weaknesses associated with design and analysis strategies. Areas of consensus are summarized. (SLD)

A method is described for increasing residual degrees of freedom in a community experiment without substantially increasing cost or difficulty by dividing experimental subunits into batches. Theoretical advantages of batch sampling are described and illustrated with data from the Pawtucket Heart Health Program. (SLD)

Two studies used experimental data to evaluate nonexperimental methods of program evaluation for employment and training programs. Results of both studies indicated that the nonexperimental methods might not accurately replicate the experimental estimates. Also, new methods for constructing comparison groups yielded little improvement over…

Estimates of the Comprehensive Employment and Training Act's net impact on participant earnings, using Continuous Longitudinal Manpower Survey data, were compared to a similar sample from the Current Population Survey. The use of multivariate matching and weighting yielded acceptable results. (GDC)