Understandability
Why Understandability? | How You Can Achieve Understandability
Software should be comprehensible for users – not only for its creators. There are many aspects to understandability: Application structure, navigation, procedures, terminology. Or more concrete: This principle requires that users always know the state of their task, what to do next, how the application reacts to certain inputs, and so on.
See also Understanding, Learning and Relearning for more information and examples on this topic.
Why Understandability?
Understandability is an ultimate prerequisite in order for users to perform any task. The better users understand an application, the more effectively they can use it because they know a greater portion of the application's functionality. This also leads to more efficiency because they can use functionality that achieves goals faster, with fewer steps, and fewer errors.
Understandability is closely related to learnability. The easier an application is to understand, the easier it is to learn and relearn. Understandability is also closely related to and an aspect of transparency. The more transparent an application is, the easier it is to understand, and vice versa. Last not least, principles such as self-descriptiveness and feedback help you to realize understandability.
How You Can Achieve Understandability
An application may be understandable for the following reasons:
- The application is small and simple
- The task and its procedures are self-evident
- The application explains itself (self-descriptiveness)
and thus is understandable through cues, such as:
- Screen, area and group titles indicating the purpose of the respective interface element
- On-screen instructions, diagrams or affordances
- Metaphors
- Explanations (more or less extensive) that are available on request. Whether these explanations actually make an application understandable, depends on the quality of the explanations and the language they use
- There are no implicit or tacit assumptions about how users are expected to behave, particularly none that contradict users' expectations
- Feedback is given on user actions, system actions, and the system state
See also Understanding, Learning and Relearning for more information and examples on this topic.
Source: Simplifying for Usability