We summarize findings of one case from initial in-lab usability and cognitive tests of 13 clinicians using MedWISE, a widget-based electronic health record (EHR) interface, to familiarize themselves with real patient cases and verbalize their assessment and plan. Multiple methods were used to examine patterns of use, time taken, use of new functionality, user-created interfaces, and diagnostic and human-computer interaction processes. All clinicians learned MedWISE quickly, most used more than half the new functionalities and found MedWISE easy to use and useful. We discuss implications for the design of future EHRs.