The problem(s) with sitemaps.

"Where am I?", is said to be the first question maps should answer. On the net, it competes with "What else is there?"

I believe the most important thing to consider when building a sitemap is what kind of experience do you want to give the user.

What a map should be like.

What a map does better than just a listing of what's available (like CNN's so called sitemap, which is basically just a huge list that makes it really hard to find something without reading it all), is to show relationships and information about the information. (I'll use the word metainformation here, for lack of a better one) This can be done by color coding (red is critical info, grey is neutral info for example), or drawing lines between/around related pages, or grouping related info (think YAHOO), or many other ways.

The point is that the user should be able to look at the map and quickly decide which areas are of interest to him.

But let's talk about the user's experience. Why do they use a sitemap? "To find stuff, silly!", I can hear you think. Right. But what experience are they after?

1. They are looking for a very specific piece of information on your site. So what does this mean? First, that your search engine isn't very well optimised. However, since you're offering a sitemap is should allow visitors to locate something specific they're looking for. Therefore, it should be complete. (This doesn't mean it can't have different levels of course)

2. They were surfing your site and are looking what else they there is they might enjoy. The keyword here is "enjoy". I believe this is the most common user behaviour. A complete listing of content isn't enough, the sitemap should give users a fast way to decide which information is of interest to them. It should give metainformation.

You could try to define the different kinds of users you've got (by making scenarios, ?) and like this define what content would be of use to what type of user. For example, I have a site with information about Colombia. It can be divided in travel info, work info and other info. So I made a sitemap with color coding to show users in a glance which info would be of interest to them.

Other metainfo about pages on your site can be: popularity of each page, how new the pages are, ?

Think about it. Would the CNN sitemap be more usable if it provided some kind of metainformation? Maybe just put the most popular sections in bold?

Let me stress this: the metainformation should reflect the needs of the users, not the organisation of the company or any other criteria. So think about your users, what kinds of experiences they are having on your site (if you haven't already).

So we've concluded what a sitemap should be like: a) complete, and b) give metainformation that reflect the users' needs.

Cool. So why are so many sitemaps so hard to use?

The problem with sitemaps.

One problem with all maps is of course the amount of detail you include. Not giving enough information about the choices confuses the user. One of my own sitemaps suffers from that: at the bottom of each page (which avoids another pitfall with sitemaps: you have to go to them, which means wait for them), it's called "at all the pages on this website.", and it just lists the names of the pages plus some extra information about what kind of page it is.

Just as bad is giving too much information about the choices. Consider an old sitemap for the same site. It'll take you ten minutes to read it all! More of a novel than a sitemap.

Graphical sitemaps (a 2.5 isometric Z-diagram for the same site again) of course have the disadvantage of loading too slow.

So it's not easy to build a good sitemap, and there are no solutions that'll work for all sites. User testing is in order here!

More reading.

The best place to start is this article about website mapping at mappa mundi, an excellent site about maps in general.