Usability Evaluation of a Voluntary Patient Safety Reporting System: Understanding the Difference between Predicted and Observed Time Values by Retrospective Think-Aloud Protocols

The study evaluated the usability of a voluntary patient safety reporting system using two established methods of cognitive task analysis and retrospective think-aloud protocols. Two usability experts and ten end users were employed in two separated experiments, and predicted and observed task execution times were obtained for comparison purpose. According to the results, mental operations contributed to the major effort in reporting. The significant time differences were identified that pointed out the difficulty in human cognition as users interacted with the system. At last, the data collected by retrospective think-aloud technique, e.g. the response consistency on structured questions and the user’s attitudes, revealed the frequent usability problems impeding completion of a quality report.