When applications work in a manner that is consistent with other applications, users enjoy a feeling of immediate confidence in their ability to master the new program. Also, they are pleasantly surprised when trying new functions because, although new, the functions seem familiar. This does not mean that components look exactly the same, but that the internal layout of components should be the same. Elements of appearance such as color, size, and thickness of beveled edges are less important to application interoperability. Component design and layout are described in the reference section for each component and also in Component Design .
Interaction is familiar.
When interaction is different among applications, it confuses the user and makes it difficult to concentrate on the task of the application. This applies to the behavior of components, input methods, selection models , and keyboard navigation . Interaction is described in Interaction . Components are organized in a familiar manner. The user needs to be able to quickly find the proper component for each task.