Product Management: Foundations to Practice · Working with Design and UX
Usability Testing Basics
Usability testing reveals what internal review never can, because the team that built a feature already knows how it's supposed to work. This chapter covers how to run a test that produces genuine signal.
Usability testing involves observing real or representative users attempting to complete specific tasks with a product or prototype, revealing points of confusion that would be invisible from internal review alone, since a team that built a feature already understands how it is supposed to work in a way a first-time user does not. This is a structural blind spot, not a matter of the team being careless; deep familiarity with a system's intended logic makes it genuinely difficult to notice where that logic is not obvious to someone encountering it fresh.
- Internal review misses usability issues because the team already understands the intended logic, a structural blind spot.
- Testing with roughly five users per round tends to surface most major usability issues, a well-established heuristic.
- Facilitators should never guide a stuck participant toward the correct path, since that defeats the test's purpose.
- Usability testing can and should happen on low-fidelity prototypes, before engineering investment multiplies the cost of a fix.