IBM:

"The best time to use an information architect is at the very beginning of the development effort. Just as you wouldn't call a real architect to a building site just as the roof is being placed on rickety walls, it's generally a good idea to call in an expert before running into trouble with a Web site. [...] An information architect's main concern is to build information structures that are easy to comprehend and use. To do this, he must align the goals of the business with the goals of the users, and at the same time work within the constraints posed by the project (deadlines, resources, budget, etc.), technical issues (choice of development language, database, etc.), and content production (staffing, depth of in-house/freelance talent, etc.)."