Many functional, technical and perceptual considerations must be met before a workstation will be adequate for primary diagnosis. The focus of this paper is the functional aspect of the workstation. Specifically, we are concerned with determining how images and data must be presented to the radiologist, for the purpose ofprimary diagnosis, under the constraints imposed by the digital workstation. We have developed an interface that is being used to acquire detailed information about the current diagnostic process. The purpose of this interface is twofold. First, this interface enables us to monitor the image and information access patterns of the radiologists in the process of interpreting films. This information will be used to automate the presentation of images and information to the radiologist in future cases. Second, this interface provides a continuously evolving tool to capture the physical attributes, or navigational cues, necessary for the radiologist to develop a mental model of the operation of the diagnostic workstation. This report describes the current operation andfuture goals of this inteiface.