Quite a good article at Boxes and Arrows on "Four Modes of Seeking Information and How to Design for Them"
In a complex web system, ie: large organizations; universities etc. where there are many difference audiences each with specific content needs, it can be quite the challenge to anticipate or logically determine how they might be seeking the information they need. Do they know what they want to find? Can they describe it? Is it something they found before and are trying to locate it again? Are they searching for something when they really need something else? These are the questions that Donna Maurer examines in the above mentioned article. Well worth reading.