What kind of testing ensures an application’s user interface is intuitive?

Usability testing is specifically designed to evaluate how user-friendly and intuitive an application’s user interface is. This testing involves observing real users as they interact with the application to determine how easily they can navigate and accomplish tasks. The primary goal is to identify any areas of confusion, difficulty, or frustration that users may experience, which directly impacts their overall experience with the application. By focusing on user interactions and behaviors, usability testing provides valuable insights into the effectiveness of the interface design and functionality from a user's perspective.

The other types of testing listed do not focus on the intuitiveness of the user interface. Performance testing assesses the application's responsiveness, speed, and stability under various conditions, but it does not evaluate user experience. Smoke testing is a preliminary check to ensure basic functionality is working, ensuring that new builds are stable enough for further testing but does not delve into usability aspects. Exploratory testing is an informal testing approach where testers explore the application without a structured test plan, which might highlight some usability issues incidentally, but it does not systematically evaluate user interface intuitiveness.