Hierarchy and the Filing System - Page 3

That there should be a hierarchy is almost mandated by considerations such as user familiarity, file system structure, etc. We instinctively think in terms of topics and their subtopics, and map these to file-system directory trees in our Web sites.

Note that content structure actually has two major levels: how you implement it (e.g. in the filing or database system), and how the users see it in navigation facilities. They don't at all have to be the same thing, because the user isn't looking directly at your filing system; they will see it through links or redirects or intermediate software. This indirection can provide you with some flexibility as your site evolves. Your initial filing scheme might prove to be less than ideal; you notice that users are going to a page or set of pages that you'd placed deep down in the hierarchy, and so you would prefer them to be prominent on the navigation menus. Not a problem, those menus don't have to mirror the server's filing system! However, we prefer to keep them synchronised (on the K.I.S.S. principle) and occasionally move files or directories — taking care to add server redirects.

Hierarchical organization imposes a useful discipline on your own analytical approach to your content, as hierarchies only work well when you have thoroughly organized your material. I recommend putting a lot of effort into designing a logical system based on the user's view — rather than say, departmental structure, though that might play a role. Your navigation system should then be able to take advantage of the file structure, and good keywords will appear in the URLs themselves, helping users figure it out.

Shortcomings of Strict Hierarchy

Comfortable as it may be, there are various problems with strict hierarchies:

• Web pages don't always fit neat single categories; they might well span several, e.g. mathematics puzzles. In fact, most topics or Web pages span related topics to some extent.
• Hierarchies are inflexible; it can be hard or inconvenient to re-assign items if a mistake is uncovered, or your initial placement was not ideal, or the field evolves in an unexpected direction, or a better structure is discovered. Many major Web sites have been restructured at some time. Many of us experienced a lot of frustration when Microsoft (and others) restructured their sites and didn't bother with redirects.
• Hierarchical classifications are prone to subjectivity and cultural bias. Look at DDC and you'll probably guess that it was devised by a Christian American over a hundred years ago. LoC has military and naval science as top-level categories. And you've probably, at some time, descended a subject hierarchy such as Yahoo!, expecting to find a topic in a certain place, but it was elsewhere (where would you expect to find "optical illusions"?)
• Rigid hierarchical classification schemes cannot keep up with scientific advances. Sections of the widely-used schemes — notably Dewey — are restructured periodically, but there are always protests from the library community when the revisions necessitate reclassification of large parts of a collection.
Separation of Concerns - Page 2
Design and Architecture of a Content-Rich Web Site
Growing Hypertrees - Page 4