Guideline summary

The navigation style should depend on the operator's familiarity and practice in approaching the desired feature

Direct access

Direct access is best for control features that the operators need to access frequently. No guidance is required, because the operators learn, after getting some experience, where to find the access point. Direct access is applicable to small sets of fixed items.

For occasional feature search, it should be limited to three to seven items. For repetitive access, it may be extended to 30-70 items.

Guided access

Guided access is best for features that the operators need to access rarely, when they are not familiar with the access point, and guidance is required. guided access enables coping with the limitations of the working memory . It is best when the search is from large sets of variable data. It is best for emergency operation.

Searching

Searching is required for cases when the operators do not know or do not recall the access point.

Apply indexing and keyword search to dynamic information and to filtered information, such as by queries. It is best suited for handling complex situations, for problem solving, such as in troubleshooting.

Key attribute: the frequency of feature use

The method applied to access a particular feature should be chosen according to the forecast of frequency of use of that feature:

If we estimate that the feature will be used frequently, the optimal navigation method is by direct access. This means that the access to the feature is through a dedicated control screen, providing access to many features (of similar forecast). The reason for this is that the operators are familiar with these screens, and know where to find the proper control
If we estimate that the feature will be used rarely, the optimal search method is the Interactive Search. This means that the access to the feature is through a dedicated control screen, providing access to few features. The reason for this is the operators are not familiar with the access to the feature, and the interface may guide them with the access to the feature.