I was talking today with Michael Kieran, our newest Customer Success Manager at Socialtext, about structure in wikis. As I've blogged about before, it's very important for a wiki to have some structure. WIthout structure, people get confused, lost, and according to my friend Barry Schwartz the author of the Paradox of Choice, depressed. At the same time, there's nothing more annoying than an overstructured website, where you have to click through link after link after link to get to the content you care about. How do we reconcile those two observations?
The answer is that a good wiki is structured around a pyramid, rather than a hierarchy.
Content in a wiki should never be more than one click away. Beyond the first page of the wiki (and maybe not even then), there should never be pages that are just pages of links. At the same time, all of that content should follow the Pyramid Principle on which these are articulated at a high level first, then articulated in more detail further down. In other words, every wiki page should have content, but that content should contain structure (via links) that take the user down into more detail, or sideways into related topics.
Wikipedia is a great example of this, and I think it's one of the reasons why Wikipedia is so popular. Every Wikipedia entry has content. You don't have to click through a bunch of links to get to the good stuff. At the same time, each entry is chock full of links that take you into greater detail.
However, there is one important way in which the pyramid metaphor breaks down on a wiki: a link on a wiki doesn't necessarily take you into greater detail; it may take you sideways into a different topic.