Concurrent vs. post-task usability test ratings

This test of rating scale use showed that there were significant differences between questionnaire ratings when users were asked to rate task ease and enjoyment during task execution (Concurrent) vs. after task completion (Post-Task). Results suggest that users' Post-Task ratings may not accurately reflect their actual task experience. Results also suggested that there are qualitative differences between user verbal protocols between the Concurrent and Post-Task groups. Implications for use of test ratings scales are discussed.