Which type of usability testing involves direct interaction with users?

The type of usability testing that involves direct interaction with users is moderated testing. This method typically includes a facilitator or moderator who guides participants through tasks while observing their behavior and collecting insights in real-time. The presence of the moderator allows for immediate clarification of questions, further exploration of user thoughts, and deeper engagement, which can lead to more detailed feedback and a better understanding of user experiences.

In contrast, formative testing may occur at multiple stages of the design process to gather feedback and make iterative improvements but doesn’t necessarily involve direct interaction in the same capacity as moderated testing. Summative testing is typically conducted after the implementation of a design to evaluate its effectiveness and may or may not involve direct user interaction, often focusing more on quantitative aspects. Unmoderated testing, meanwhile, allows users to complete tasks independently without the presence of a facilitator, thus lacking the direct interaction characteristic that is pivotal in moderated testing.