Skill development is fast when the operation is consistent, namely, when the results of an action do not depend on context. When the response to actions is inconsistent, the user should be aware of the context that determines the system response. The user response time is delayed because of the need to perceive the situation, and the reliability is reduced, due to occasional perception errors. Consistency enables seamless operation, saving the user’s need to pay attention to system or interface variables. In addition, consistency increases user reliability.
Skill development is enabled when the context is salient. If the context is not apparent, users need to either memorize the relevant context variable or look for it in the interface. Relying on the memory is error-prone and looking for it in the interface is time consuming. In both cases, the user performance is degraded considerably.
Updated on 09 Mar 2016.