For this paper we rate each as high, medium, or low, although more fine-grained numeric scales are also effective. As another example, if Learnable is rated high and Understandable also high, then the problem is easier to solve, and indeed there is a known solution providing the user with a good conceptual model. Because there can be only a limited number of combinations of high ratings on the limited list of attributes, we can hope for known solutions to exist for many of them and for a focused search to uncover many others. This section identifies three types of usability patterns, Simple, Intrinsic, Circumstantial, each with an example. Simple Patterns One usability attribute dominates, and solutions are easy.
Efficiency is most important by far.
Support very fast manipulations. Minimize action at the articulatory level through button bars, toolboxes, accelerators. This pattern can be observed in almost any modern word processor or graphic editor. Intrinsic Patterns Multiple usability attributes conflict or support. These may pose difficult problems, but many are already solved.