The paper provides detailed descriptions of general practitioners (GPs') interactions, both with their computers and their patients, with the aim of facilitating the detailed understanding of how GPs use their computers while in consultation with patients. The focus is on the coordinated activities of the doctor and patient and the multitasking that is required during consultation. The data consists of primary care doctor-patient consultations for asthma and angina where clinical scenarios, supported by dummy electronic and paper records for use by the doctor, were played out. Although not 'naturally occurring', the mock scenario is a traditional medical training technique. Objective and methods: This paper describes and demonstrates a data transcription methodology, involving seven discrete levels of activities, developed to account for the intricate multitasking that occurs in a GP consultation. The transcription method, developed to support the evaluation of a prototype medical prescribing decision support system (Prodigy) for use by general practitioners in consultation with patients, builds on data description techniques from conversation analysis (CA) and video analysis (VA). Conclusions: It is suggested that the methodology described could also be applicable to other scenarios involving the observation of human-computer-human interaction.