This paper describes a methodological framework for conducting evaluations of clinical workflow and system impact based on simulated user interactions. The approach involves collection of a rich set of data consisting of audio and video recordings of interactions of healthcare workers with health care information systems and their associated devices. Methodological considerations and issues in conducting such studies are discussed. The steps involved in carrying out such studies are described along with a description of our current work in the application of the approach to the analysis of clinician workflow.