Leading social research methodologists and evaluators explore research design issues in this second of two volumes inspired by the work of Donald Campbell and sponsored by the American Evaluation Association. The authors address such issues as quasi-experimentation, the proper conduct of social inquiry, ways to take account of threats to validity, plausible rival hypotheses in measurement and design, subject selection and loss in randomized experiments, the use of evaluation to assess the validity of computer simulations, method variance, and time series experiments. Applied researchers who want to improve their research designs will find this book a compelling and thought-provoking read.