CT-UT ISTQB Certified Tester Usability Tester Question and Answers

Common mistakes in usability testing include:

Ignoring critical results (ii): A significant issue if findings are not acted upon.

Scheduling the test too late (iv): This can lead to usability problems being discovered too late to be addressed effectively.

Having the wrong focus (v): For instance, focusing on aesthetics instead of usability goals.

Option i ("user is too active") is not a problem—active participation is necessary. Option iii ("no observers involved") is not a typical mistake, since tests can still be valid even with recorded sessions and later review. Hence, the correct answer is A: ii, iv & v are true.

SUS (System Usability Scale), SUMI (Software Usability Measurement Inventory), and WAMMI (Website Analysis and Measurement Inventory) are all validated, standardized usability questionnaires that support benchmarking. They allow comparison against known usability scores from a wide variety of systems. These instruments provide numeric scores that can be interpreted using benchmark datasets or industry standards. Therefore, all three—i, ii, and iii—are true, making D the correct answer.

Usability test reports are more effective when they are balanced and include not only problems but also what worked well. Including positive findings increases credibility, encourages the development team, and helps them understand what should remain unchanged. Option B violates privacy and ethical standards. Option C may dilute focus, and D could worsen the problem by making the report less accessible. Thus, the best practice supported by usability.gov and Nielsen Norman Group is to include both positive and negative findings.

Formative usability evaluation is conducted during the development process to identify usability problems and improve the product iteratively. It is diagnostic and improvement-focused. Summative evaluation, on the other hand, is done after development to assess the final product’s usability, measuring how well it meets defined usability goals. Therefore, the correct distinction is that formative evaluation focuses on improvement, and summative evaluation assesses the outcome. This distinction aligns with widely accepted models such as those defined by ISO 9241-210 and usability.gov.

A usability test session is a controlled period during which a test participant performs tasks using the system under test while being observed by a moderator and sometimes additional stakeholders or observers. The goal is to understand how users interact with the interface and identify usability problems. Option A describes an individual task, not the whole session. Option C refers to a test plan or test script, and Option D describes a test technique rather than a usability session. Thus, option B provides the most accurate and comprehensive definition.

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.

The usability tester, often synonymous with the usability test moderator in practice, is primarily responsible for interacting directly with the test participants during the usability testing sessions. This role includes communicating with participants to guide them through test tasks, answering questions without leading responses, and ensuring the session runs smoothly. Effective communication is essential to facilitate participant comfort, elicit genuine user behaviors, and capture accurate usability data.

Performing the pre-session briefing (Option A) may be done by the usability tester but is often a shared responsibility or part of test facilitation protocols. Discussing findings (Option C) typically falls to analysts or usability experts after testing sessions are completed and data analyzed. Defining testing tasks (Option D) is usually done by test designers or analysts during test planning, not during the test execution.

Therefore, communicating with test participants during testing is a core, principal task of the usability tester role.

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.

A pilot usability test session is a critical step prior to conducting the actual usability test. Its purpose is to ensure that the test setup, task design, and moderator instructions are clear and function as expected. According to ISO 9241-210 and the Nielsen Norman Group's best practices, pilot testing helps detect unforeseen issues and fine-tune the process. Options A and B are incorrect because testing conditions must reflect realistic scenarios, and thorough preparation is essential to gather meaningful usability data. Option D is also incorrect; a usability test typically consists of multiple sessions with different users to gather sufficient data for analysis. The pilot session ensures everything works smoothly before involving real participants.