Program evaluation is not among the most popular of exercises, since it carries risks for all associated with it. Because every important program has friends and enemies anxious for its prosperity or demise, the investigators and their findings will normally be attacked from at least one side and not infrequently from both. But this is an occupational hazard, dutifully accepted by its practitioners; for some it even adds a zestful touch of danger. However, the program's sponsors and its participants require an unusual degree of courage, since negative or indifferent results are not...