Computerization of general practice is an international phenomenon. Many of the Electronic Patient Record (EPR) systems have developed organically with considerable variation in their interface and functionality. Consequently they have differing impact on the clinical consultation. There is a dearth of tools available to study their impact on the consultation. The objective is to use ALFA to film and analyze a simulated clinical consultation. We used the ALFA (Activity Log File Aggregation) open source toolkit, to make video based observation and analysis of the computer mediated consultation. ALFA enables precise comparison of core elements of EPR systems. It allows multiple video channels including screen capture, data about computer use, and verbal interactions to be synchronized, timed and navigated through for analysis. The toolkit is free and can be downloaded under an open source license from www.biomedicalinformatics.info/alfa/. Its outputs, which include Unified Modelling Language (UML), provide the evidence-base for assessing the impact of the computer on the consultation the designing of EPR systems. ALFA has been used to compare different brands of primary care computer systems; nurse case-load selection and consultation in psychiatry.