This paper considers the possible effects of making inferences about individuals from aggregate data. It assumes a knowledge of regression analysis, and explores the utility of techniques designed to make the inferences in causal modelling more reliable, including a comparison between ecological regression models and ecological correlation.

This readable and comprehensive text is designed to equip students and practitioners with the statistical skills needed to meet government standards regarding public program evaluation. Even those with little statistical training will find the explanations clear, with many illustrative examples, case studies, and applications.

Far more than a cookbook of statistical techniques, the book begins with chapters on the overall context for successful program evaluations, and carefully explains statistical methods--and threats to internal and statistical validity--that correspond...