BACKGROUND: The Infobutton Manager (IM) is an application that provides clinical users with context-specific links to health information resources. Usage of the first version (IM-1) suggested that the user interface was suboptimal. METHODS: We conducted a laboratory-based observational study of IM-1, use, applied standard user interface design techniques to address observed problems, developed a new version (IM-2), conducted a second observational study and analyzed log files of the actual use of IM-1 and IM-2. RESULTS: Modifications to the IM resulted in a reduction of "perusal time" (time between evocation of the IM and selecting a topic) from 11.13 to 5.92 seconds. However, evaluation of 14 months of usage logs did not show an appreciable effect on the perusal time or the rate at which users selected a topic once the IM was evoked. CONCLUSIONS: Laboratory analysis of the IM was evoked. CONCLUSIONS: Laboratory analysis of the IM guided redesign that led to improved performance in the laboratory, but did not address factors that are influencing use.