The navigation aspect of a site must be intuitive for a first-time visitor; there are no second chances at making a good first impression. Navigation mechanisms that make it hard to find relevant information are discouraging, and users will lack the motivation to visit the site again. Although appropriately organized content is the first step toward creating a user-centric information access taxonomy, this taxonomy is ambiguous unless associated with a context. Navigation schemes complement the content taxonomies by providing the needed context, and they are augmented by an appropriate labeling scheme.
There are several approaches for creating an appropriate navigation scheme. Some of these approaches are explained in the context of the sample application as follows:
Global The primary navigation bar of a site usually provides access to coarse-grained functionality with the capability to navigate both laterally and vertically through the site; this navigation bar is often referred to as the global navigation bar because the navigation elements are accessible consistently across the entire site or across conceptually and semantically related pages, also called subsites. Most sites are designed with global navigation at the top or bottom of the page.
Local When the page hierarchy is traversed, we encounter several pages that are gateways to fine-grained content or functionality. A marketing page will have an information hierarchy that is different from the customer service page. To accommodate for functionally different subordinate information hierarchies, we use local navigation bars to support the navigation semantics that are specific to each of the subordinate information hierarchies. You can think of a local navigation bar as a form of nested navigation. In the sample application, each administrator page differs in the navigation elements available to the type of administrator interacting with the system; as shown previously in the section "Organizing Content," the applicable local navigation bar for each type of administrator appears at center-left of the page. The selection of a navigation element in a local navigation scheme is often accentuated, for contextualization, by highlighting the selected element.
Bread crumbs When shopping in Mall of America, we get our bearings by looking at "You are Here" signs. In a complex navigation scheme, it is always good to let the users know their locations within the overall site, and provide trails that they can take to get to certain pages; hence the bread crumbs analogy. Usually, an additional navigation bar is inserted at the top within the content portion of the page. This additional navigation bar is of the form Element1 > Element2 > Element3; selecting Element3 in the previous page results in the delivery of content for the current page.
Site map A site map aggregates the navigational elements of a site. Representing a complex site structure using a site map could quickly clutter the map and make it unwieldy. Provide only the navigation elements essential to portraying the site's purpose while implementing a design that harmonizes form and function. The site map never provides an entry point in the middle of a workflow because this will jeopardize the transactional semantics of an application, which in turn could pose a serious security and data integrity risk.
TOC A table of contents is often used for content that is hierarchical in nature. Sites offering user guides and documentation usually sport an ad hoc navigation scheme built around a table of contents. A TOC can be implemented inline with page transitions or as a separate window.
Embedded links Often links are embedded within the content for creating an ad hoc navigation scheme.
Adaptive A navigation scheme can adapt to reflect a user's preference and/or behavior.
An example of this is apparent at online retail stores where a shopper could have additional navigation elements on a page added as a result of his or her shopping pattern.