Longitudinal studies use some of the psychological and psychiatric tools typical of clinical criminology, such as personality tests, behavior observation, rating scales, and interviews. On the other hand, clinical studies analyze motivation, conflicts, and past experiences to arrive at conclusions. Longitudinal studies are based mainly on quantitative and objective investigation, while clinical studies largely involve qualitative and subjective analysis. Elements common to longitudinal and clinical research studies are examined, as well as benefits of both research approaches in the study of human development and criminal behavior. The authors warn against automatic and uncritical uses of longitudinal research results because such uses may lead to oversimplified clinical criminology. 22 references