This book focuses on methods of choice in program evaluation. Credible methods choice lies in the assumptions we make about the appropriateness and validity of selected methods and the validity of those assumptions. As evaluators make methodological decisions in various stages of the evaluation process, a number of validity questions arise. Yet unexamined assumptions are a risk to useful evaluation. The first edition of this book discussed the formulation of credible methodological arguments and methods of examining validity assumptions. However, previous publications suggest advantages...