CT-UT ISTQB Certified Tester Usability Tester Questions and Answers

Option B represents a realistic, goal-oriented scenario that reflects how an actual user would interact with the website. It incorporates context, user intent, constraints, and desired outcome—all characteristics of well-designed usability tasks. Option A is vague and lacks real-world motivation. Option C is too prescriptive and limits insight into user behavior, while D is a survey question, not a usability task. According to Nielsen Norman Group and ISO 25062, the best usability tasks are scenario-based, realistic, and outcome-driven—making B the correct answer.

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.

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.

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.

Moderating the usability test is a core activity during the actual usability test session. The moderator guides participants through tasks, ensures the session stays on track, and avoids introducing bias. Option A (testing the setup) happens before the session, during preparation. Option C (extracting findings) occurs during analysis, after the test. Option D (talking during task execution) should be minimized unless necessary, to avoid influencing user behavior. Therefore, option B is the only correct answer aligned with best practices in usability testing.

When actual users cannot be included, a usability review (often an expert or heuristic evaluation) is the most practical method. Trained evaluators examine the interface against usability principles and standards to identify potential issues. Surveys require user input, and usability testing cannot proceed without users. Accessibility evaluation targets inclusivity for users with impairments, which is related but not a substitute for overall usability evaluation. Therefore, option A is the only valid method under these constraints.

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 Web Content Accessibility Guidelines (WCAG) provide standards to ensure websites are accessible to people with disabilities. They specifically address:

i. Text resizability (SC 1.4.4),

iii. Text alternatives for non-text content (SC 1.1.1),

iv. Keyboard accessibility (SC 2.1.1),

v. Device independence, which includes not relying solely on mouse input.

Visually appealing design (ii) is not an accessibility requirement and is thus not a WCAG focus. The correct answer is D: i, iii, iv & v are true; ii is false.