Practice Free CTFL-UT ISTQB Certified Tester-Foundation Level - Usability Testing Exam Questions Answers With Explanation

The System Usability Scale (SUS) is a standardized, reliable tool used to measure perceived usability. It consists of 10 items with five response options (from strongly agree to strongly disagree). It is widely used due to its simplicity and effectiveness in providing a single score to reflect a user’s overall satisfaction with a system. Option A refers to ISO's definition of usability testing, B describes a task in usability testing, and D refers to a usability requirement, not SUS. Therefore, the correct description of SUS is option C.

A best practice in usability reporting (based on ISO/IEC 25062:2006 – Common Industry Format for usability test reports) is to include a clear description of the evaluation method used. This includes how the test was designed, how participants were selected, what tasks were performed, and under what conditions the test was conducted. This ensures the results are credible and reproducible. The provided structure omits this essential information. While the report length is not excessive and positive findings may or may not be present, the key missing component is the method description.

A usability requirement specifies how usable a product or component must be, often in terms of effectiveness, efficiency, and user satisfaction, as defined in ISO 9241-11. These requirements ensure that the product meets specific human-centered design goals, such as allowing users to complete tasks accurately and quickly. Options A and C describe procedural or test setup elements, not actual usability requirements. Option B refers to personnel qualifications, which are not the same as usability requirements related to system behavior or performance.

A usability test participant is a person selected to represent the target user group and asked to perform specific tasks in a usability test. Their actions, reactions, and feedback help identify usability issues and evaluate the system’s effectiveness, efficiency, and user satisfaction. This role is strictly observational and does not involve organizing, observing, or setting up the test. Options A, B, and C describe other roles (e.g., technical support, observers, or moderators). Only option D accurately reflects the definition of a usability test participant.

Usability is defined in ISO 9241-11 as the extent to which a system can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use. Without knowing the context—such as product complexity, user familiarity, device type, or purchasing habits—it is impossible to judge whether five minutes is good or bad. For complex items, five minutes may be reasonable, while for one-click purchases, it may be excessive. Thus, usability cannot be assessed solely based on one metric like time—it must be evaluated within its full usage context.

The human-centered design process emphasizes iterative development—testing and refining designs through multiple cycles. In the scenario, the project manager interviewed users and evaluated a prototype but did not iterate based on feedback. Skipping iteration likely resulted in unmet user needs. Human-centered design, per ISO 9241-210, includes: understanding context of use, specifying requirements, producing design solutions, and evaluating—repeated iteratively. Hence, option D (“iterate”) is correct.

A usability test script is a structured document used by the moderator to ensure consistency across test sessions. It typically includes pre-session briefing text, pre- and post-session interview questions, and the specific usability tasks to be performed. However, it does not include answers to the test questions, as usability tests focus on observing user behavior and performance—not testing users’ knowledge. Providing answers would bias results and invalidate findings. Thus, option D is incorrect and the best choice.