Methods: Five subjects were tested on a prototype of VPSRS as they performed a reporting task by think-aloud protocols. The experimenter selected three representative incident cases from the patient fall category for the task, which cover a full scope of questions asked in the common format. An established schema of usability problem categories were applied to code and analyze the transcribed verbatim of the think-aloud reports. A follow-up interview was conducted to supplement subjects’ further comments about the prototype.