This manual introduces the Interagency Research Information System (IRIS), a database dealing with federally-sponsored research and development efforts relating to children and youth, and outlines the general uses of the IRIS database. The classification for the subject description of materials covered by the database is described and the classification scheme is presented, along with the numeric codes affiliated with the classification categories that are used in searching the IRIS file online. The general categories of information provided include general project information (e.g., funding, duration, scope, and sample size), targeted research population (by age, sex, ethnicity, socioeconomic status, and location), kind of research, focus of research, areas of research, and findings. (JL)