With the increasing longevity of our population, the problems of diagnosing and treating geriatric disorders are becoming a major public health concern. To support the clinician in the task of geriatric diagnosis, we developed a prototype expert system, INTERLOCUTOR. We now propose to convert this prototype system into an application program. A controlled test will be performed with a group of junior clinicians in a geriatric outpatient clinic. The results are intended to establish the validity of our conceptual approach in this field setting through systematic evaluation protocols. We expect this work t provide the basis for application of the INTERLOCUTOR concept to other classes of health professionals, notably para-professionals in mental health care facilities.