Research, evaluation, and policy analysis are elements of inquiry whose functions, aims, purposes, intended audiences, and intended outcomes have been confused in the literature discussing how to accomplish them. Using the definition of "disciplined inquiry" provided by Cronbach and Suppes (1969), which defines disciplined inquiry as the resolution of a problem to achieve understanding or to facilitate action, an analysis is made of each research, evaluation, and policy analysis. Each is found to fit within the definition of disciplined inquiry, and then each is dissected to compare purposes, audiences, and intended outcomes. Proposed for each is a new definition that incorporates the forms, functions, audiences, and outcomes. A bibliography is included. (Author/TE)