Lesson 6: Usability Testing and Evaluation

HCI evaluation ensures the design works for users. Two main approaches are formative (ongoing testing during design) and summative (final testing after design). Popular methods include heuristic evaluation (experts check the interface against established heuristics) and user testing (watching real people use the interface). You might learn to plan a usability test: define tasks, recruit 5–10 representative users, observe them performing tasks, and record issues. Philippine coursework often has students do guerrilla testing with classmates or deploy surveys for feedback.

During tests, we measure metrics like time on task, error rate, and satisfaction scores. For example, the System Usability Scale (SUS) is a quick survey giving a score from 0–100. If your app scores below ~68, it's generally considered below average. You should also gather qualitative feedback: ask users how they felt about the interface. A common tip is the "think aloud" protocol, where users say their thoughts while using the system. After testing, analyze results: find patterns (e.g. all users stumbled on one button), then fix those issues. This cycle of "test, learn, iterate" is at the heart of the HCI curriculum.

Ready to apply this? The practice set below walks through exam-style problems with step-by-step solutions and a usability evaluation plan.