In assembling almost three dozen papers which bear upon the evaluation of health programs, we have tried to select those materials which could meet the needs of both researchers and program directors. It is believed that in spite of the well-known differences in orientation and priorities which these two groups frequently exhibit, nevertheless there exists a wide span of common concern which needs only to be properly plumbed. To capitalize upon the mutual interests of researchers and practitioners and to demonstrate opportunities for fruitful collaboration, we have emphasized papers of potential interest to both groups and avoided selections which were overly skewed toward the needs of only one of them. Many other sources are available for the study of program development or research methodology but this volume one differs in its attempt to integrate what generally have been dichotomous fields of interest. Volume II was a response to the escalating demands for accountability, increasingly complex conceptual and methodological options, and a proliferating literature require that sophisticated materials be readily available if assessments are to be performed in knowledgeable ways. When is paired with our earlier volume, those teaching the growing number of program evaluation courses in medical schools and schools of public health, social work, and business should have more than enough reading materials for their introductory and advanced seminars.