Which type of testing allows for subjective evaluation of user interfaces?

Manual testing is the type of testing that allows for subjective evaluation of user interfaces. This approach involves human testers who interact with the application to identify issues, assess usability, and evaluate the overall user experience. Since manual testing is driven by human observation and opinion, it is particularly well-suited for assessing aspects such as design, layout, and the intuitiveness of the user interface, which automated tests may not effectively capture.

The subjective nature of manual testing means that testers can provide feedback on how user-friendly an interface is and how it meets user needs, which is crucial for applications where user experience is a primary concern. This method allows for flexibility in testing and can adapt to varying criteria that might not be quantifiable or easily assessed by automated scripts.

In contrast, automated testing is focused on executing predefined scripts without human intervention, which limits its ability to evaluate aspects of user experience that require a subjective touch. Regression testing is primarily concerned with verifying that previously developed and tested software still performs after changes have been made. Unit testing focuses on validating individual components of the software for correctness rather than assessing the user interface as a whole.