I’ve never been a big fan of sitemaps on Web sites, perhaps because I’ve too often seen them done badly, presented as a graphic copied straight from the visual tool used by the information architect. Some say a sitemap is an accessibility requirement but surely this is only true if your navigation doesn’t function under all conditions – and if that’s the case you may wish to re-think the implementation of your navigation.
That said, sitemaps can be a useful supplement to navigation and search, and can certainly improve findability. A recent Boxes & Arrows article, Sitemaps and Site Indexes: What They Are and Why You Should Have Them, demonstrates how to create good sitemaps. The best ones are text-based and show the site hierarchy and organisation through a combination of layout and colour. They must also use the same labelling as the site navigation scheme to help visitors orient themselves.
At work, Multimap had a beautiful sitemap graphic, created by Nika, but it was hard to keep up to date. We’ve recently replaced it with a coloured text version based on styled nested lists which is easier to maintain, more accessible and quicker for readers to scan.