The main purpose of this paper is to delineate methods of data collection and coding currently being used in a longitudinal observational study of toddlers in 25 black families in Oakland, California. Data collection activities, accomplished through monthly three-hour visits to each home, focused on five types of data: (1) videotaped and eyewitness observations of children's behavior and interactions in their normal home environment; (2) child-focused interviews with mothers; (3) child assessments; (4) adult-focused interviews with parents; and (5) assessments of the physical environment as well as material and cultural resources of the home. Videotaping methods are emphasized and findings to date are discussed. (Author/RH)