7.7. Supplemental Navigation Systems
Supplemental navigation systems (shown back in Figure 7-2) include
Supplemental navigation systems can be critical factors for ensuring usability and findability within large web sites. However, they're often not given the care and feeding they deserve. Many site
Both statements are theoretically true but
In a book or magazine, the table of contents
In the early days of the Web, the terms "sitemap" and "table of contents" were used interchangeably. Of course, we librarians thought the TOC was a better metaphor, but sitemap sounds sexier and less hierarchical, so it has become the de facto standard.
A typical sitemap (Figure 7-17) presents the top few levels of the information hierarchy. It provides a broad view of the content in the web site and facilitates random access to segmented portions of that content. A sitemap can
Figure 7-17. Intel's sitemap
A sitemap is most natural for web sites that lend
The design of a sitemap significantly affects its usability. When working with a graphic designer, make sure he understands the following rules of thumb:
Finally, it's worth noting that sitemaps are also useful from a search engine optimization perspective, since they point search engine spiders directly to important pages throughout the web site.
7.7.2. Site Indexes
Similar to the back-of-book index found in many print materials, a web-based index presents keywords or phrases
Figure 7-18. AOL's simple but useful alphabetical site index
Large, complex web sites often require both a sitemap and a site index (and a search capability, for that matter). The sitemap reinforces the hierarchy and encourages exploration, while the site index bypasses the hierarchy and facilitates known-item finding. For small web sites, a site index alone may be sufficient. On Usable Web (see Figure 7-19), Keith Instone has made his site index even more useful by indicating the number of items behind each link.
Figure 7-19. Usable Web's highly usable site index
A major challenge in indexing a web site involves the level of granularity. Do you index web pages? Do you index individual paragraphs or concepts that are presented on web pages? Or do you index collections of web pages? In many cases, the answer may be all of the above. Perhaps a more
There are two very different ways to create a site index. For small web sites, you can simply create the index manually, using your knowledge of the full collection of content to
In contrast, on a large site with distributed content management, it may make sense to use controlled vocabulary indexing at the document level to drive automatic generation of the site index. Since many controlled vocabulary terms will be applied to more than one document, this type of index must allow for a two-step process. First the user selects the term from the index, and then selects from a list of documents indexed with that term.
Figure 7-20. Vanguard's dynamically generated site index
A useful trick in designing an index involves
, also known as
. A permuted index rotates the words in a phrase so that users can find the phrase in two places in the alphabetical sequence. For example, in the Vanguard index, users will find listings for both "refund, IRS" and "IRS refund." This supports the varied ways in which people look for information. Term rotation should be applied selectively. You need to balance the probability of users seeking a particular term with the annoyance of cluttering the index with too many
Guides can take several forms, including guided
Guides often serve as useful tools for introducing new users to the content and functionality of a web site. They can also be valuable marketing tools for restricted-access web sites (such as online
Guides typically feature linear navigation (new users want to be guided, not thrown in), but hypertextual navigation should also be available to provide additional flexibility. Screenshots of major pages should be combined with narrative text that explains what can be found in each area of the web site.
The Wall Street Journal , shown in Figure 7-21, uses a guided tour to showcase navigation and editorial features of the web site that, for the most part, are accessible only to subscribers.
Figure 7-21. The Wall Street Journal's guided tour
Rules of thumb for designing guides include:
Remember that a guide is intended as an introduction for new users and as a marketing opportunity for the web site. Many people may never use it, and few people will use it more than once. You should balance the inevitable big ideas about how to create an exciting, dynamic, interactive guide with the fact that it will not play a central role in the day-to-day use of the web site.
7.7.4. Wizards and Configurators
Though they could be
Figure 7-22. The Mini Cooper configurator
Mini successfully combines a rich suite of navigation options without
As we noted earlier, the searching system is a central part of supplemental navigation. Search is a favorite tool of users because it puts them in the driver's seat, allowing them to use their own keyword terms to look for information. Search also enables a tremendous level of specificity. Users can search the content for a particular phrase (e.g., "
However, the ambiguity of language causes huge problems with most search experiences. Users, authors, and information