The fallibility of enthusiastic claims for new drugs makes it desirable to recognize those investigations which are likely to yield substantial data and to lead to interpretations that can be ascribed to pharmacodynamic effects rather than to wish, prejudice, coincidence, accident, or error. Some new drugs, despite statistical validations in reports of their efficacy and safety, do not survive the test of actual use or, even worse, have serious repercussions. The undesirable effects of such drugs employed therapeutically already have achieved alarming proportions, being observed in approximately 5% of 1,000 consecutive recent admissions to a major hospital in the city of New York.1This situation may become even worse if the present rate of development of new drugs continues (about 550 new preparations each year or more than one every day2) and if the medical profession continues to be misled by poorly conducted or inadequate evaluations of new