Williams, W. The organization of the volume and some key definitions.--Rossi, P. H. Testing for success and failure in social action.--Houston, T. R. The behavioral sciences impact-effectiveness model.--Stanley, J. C. Controlled field experiments as a model for evaluation.--Cain, G. G. and Watts, H. W. Problems in making policy inferences from the Coleman report.--Coleman, J. S. Reply to Cain and Watts.--Cain, G. G. and Hollister, R. G. The methodology of evaluating social action programs.--McDill, E. L. [and others]. Evaluation in practice; compensatory education.--Glennan, T. K. Evaluating Federal manpower programs; notes and observations.--Kershaw, D. N. Issues in income maintenance experimentation.--Williams, W. and Evans, J. W. The politics of evaluation: the case of Head Start.--Rossi, P. H. Observations of the organization of social research.--Williams, W. The capacity of social science organizations to perform large-scale evaluative research