It's About "Findability"
Visitors don't necessarily care where something lives on the web site, as long as they have no problem finding it. Traditional navigation that reflects (usually) a site map and its hierarchy is only one way for people to go through a site. Frankly, I feel that in most cases that design is pretty straightforward; if anything, designers and stakeholders complicate things by trying to make sure that everything is "living comfortably." The site map is important, but not as important as addressing the paths that people follow through your site in their quest for information.
Stakeholders also tend to want to make sure that content is prioritized. This is fine when talking about internal goals, and has some relevance when it comes to a site's visitors, but when someone is looking for content, that piece of content she wants is the most important bit on the site. What I'm getting at is that as business goals shift and audience and user needs change, the value placed on different sections and groupings of content will change as well. It's pretty hard to create a hierarchical site map that adjusts in real time to shifting priorities, goals, and needs—regardless of where they originate. Shouldn't more time be spent addressing the user's real needs? We should be helping her to find the information she's looking for and giving her options to keep her on track when traditional navigation fails. Items like these can produce a more helpful user experience:
- Proper metadata (particularly labels and page titles) for search relevancy
- Related item grouping and linking
- Links within content
- Faceted classification and corresponding navigation
- Personalized taxonomies
- A home page that acts less like a landing page and more like an information hub (or site map—oh, the irony)
A traditional hierarchal site map can't always illustrate these features, yet often it's perceived by clients and stakeholders as the final say when organizing content. It seems to be rather difficult to get people beyond the site map, even with such tools as wireframes, content inventories, and page description diagrams. Unless all site visitors think of the content in the same way as the internal stakeholders, and everyone has the same goals and needs, relying on a traditional site map might be expecting way too much.