This paper discusses a procedure for diagnosing adult educational needs, which the author developed and tested for her doctoral dissertation to study the work performance of attendant supervisors at a mental retardation facility. She describes the methodology used as ethnographic research, which entails an analytic description of a culture by looking at an institution as a culture of its own and, for example, attempting to illuminate the meaning of a supervisor's role and perceived performance in terms of the culture of the mental retardation facility. Steps outlined as part of the methodology include identification of salient issues, development of categories of concern as areas on which to focus the diagnosis, identification of symptoms, and movement through inference to symptoms to problems to educational needs. The procedure is called responsive because it is meant to respond to the information needs of the client and rigorous because the diagnosis is done with careful description and attempts to document the bases on which judgments are made. For example, the data collection process described involves a variety of techniques: Formal and informal interviews, observation, document analysis, and questionnaires. Strengths of the procedure are also discussed. A summary of the diagnostic study conducted for the dissertation is appended. (LMS)