The current procedures in the United States for interviewing and assessing the credibility of victims, complaining witnesses, and alleged perpetrators are grossly inadequate. A comprehensive methodology is needed to remedy this problem. The two current approaches to credibility assessment are polygraph examination of accused persons and statement analysis of the child's allegations. Polygraph techniques are used extensively in the United States, Canada, Israel, and Japan, although they are not used in Europe. During 1983-85, however, 56 percent of all accused persons examined at the University of Utah by the polygraph technique were diagnosed as truthful in their denials. Since 1954, statement analysis has been the main method used by experts in the Federal Republic of Germany. This approach rests on the hypothesis that truthful and false testimonies differ in quality and content. The procedure uses a system of reality criteria developed by several European authors. New empirical findings have modified the relative importance of these criteria. Combining the techniques of polygraph and statement analysis would improve the effectiveness of the investigation process and reduce the possible negative impact on the examined child. Tables and 33 references.