Business:Concepts:Principle:PRINC-xxxx: Principle of Least Astonishment
<data principle #PRINC-xxxx>
Categories : Development
Statement : A System's design should match a User's experience, expectations, and mental models.
Rationale : In general engineering design contexts, a system's component should behave in a manner consistent with how users of that component are likely to expect it to behave.
Impact : If a necessary feature has a high astonishment factor, it may be necessary to redesign the feature.
The principle aims to minimize the learning curve, for instance by designing interfaces that borrow heavily from “functionally similar or analogous programs with which your users are likely to be familiar”.
When two elements of an interface conflict, or are ambiguous, the behavior should be that which will least surprise the user; in particular a programmer should try to think of the behavior that will least surprise someone who uses the program, rather than that behavior that is natural from knowing the inner workings of the program.
</data>