Why are manual usability tests important?

Manual usability tests are important because certain accessibility criteria cannot be tested fully automatically.

The automatic testing software reaches its limits when content or test criteria do not meet clear formal specifications and depend on meaning and context. In such cases, human understanding of intention, content and semantics is required.

Manual and automatic tests therefore complement each other to provide the broadest and deepest possible picture of the accessibility of a website, document or app.

Manual usability tests are important because they provide valuable insights into the actual user experience of people with disabilities. They make it possible to identify problems that cannot be detected by automated tests, such as unclear navigation, illogical layouts or difficulties in interacting with the user interface.

Manual tests are carried out by individuals who use assistive technologies. For example, Screen readers (see ‘What are screen readers?’) are used to check the accessibility of digital offerings.

Examples include:

Keyboard accessibility

Keyboard accessibility implies that all functions and elements of a website or application that can be operated with a mouse must also be fully and easily accessible and operable via the keyboard in order to ensure barrier-free use for all users.

Meaningful labels for interactive elements

In contrast to automated tests, which primarily focus on technical aspects such as HTML structure or code validity, manual testing allows for a more in-depth assessment of the clarity and comprehensibility of labels from the perspective of actual users, particularly in terms of context and user experience.

Hidden content

Hidden content should also be inaccessible to screen readers to prevent users with visual impairments from encountering information that is not intended for display or interaction.

Keyboard traps

Keyboard traps occur when users get stuck in a particular function or area with the keyboard and cannot leave it, which significantly restricts navigation and usability.

Moreover, manual testing with real user feedback can reveal different perspectives and behaviours that help developers and designers improve usability. In other words, they not only provide data, but also qualitative feedback that is crucial for the continuous improvement of the user experience (UX).

In addition to methodically testing elements and structures, it is also possible to run through more complex processes (use cases) to determine whether there are any hidden barriers.