In all the talk about findability, a constant theme is augmenting a sites search engine by adding synonym rings, taxonomies, and maybe even thesauri--so a search for one keyword can find a lot of related topics (or subjects or concepts) on your Web site.

It takes a lot of smart people and a lot of expensive tools to build these classification systems, and even more time and money to implement them in your search engine. Companies that can afford to buy one of everything have bought data mining and auto-classification tools to create these metadata structures. Others have hired experts with classification skills, usually former librarians now dubbed information architects, to handcraft these subject lists by talking to the people in the company and to external users like customers and partners. They identify the things people are really talking about to create a controlled vocabulary.

Taxonomies and subject lists generated by automatic tools generally get low grades when compared to similar work by human professionals. But either way, is there a reasonable payback for the large investment? Do Web site users have a different experience and more easily find the important stuff with a search engine on taxonomic steroids? The jury is still out.

In the meantime, another skilled professional that website managers should consult is an indexing professional. An indexer can make a back-of-the-book-style index of the topics on your site. It's not free. You pay modestly for the indexer's time. We're talking skilled professionals here, not software. But the return on investment is terrific, as we shall see. An index is like a taxonomy, but you don't have to integrate it into a powerful and expensive metadata-enhanced search engine. You just offer a site index, in addition to the usual site map. Think of the site map as your table of contents and the index as your, well, index.

At this point, we run into our first stumbling block. How many of you have made a decent site map? Even a good one is usually just a single page listing of the multi-level navigation possibilities of your site.

Because users have rarely been rewarded by visiting such site maps, they don't use them. Worse still is what that implies for a really useful site index. When people are asked what a site index is, some identify it as a site map. Others think it's a portal like Yahoo, with links to lots of sites.

Web site indexers need to hire a marketer like Frank Luntz, who renamed the estate tax a "death tax." We need a sexier, or at least more compelling name for a site index. And here's the evidence why:

At the May 2005 meeting of the American Society of Indexers (ASI), Ilana Kingsbury reported on usability research with a Web site index. Users were asked to find information on a site with an index link on the home page. One group was told about the index and another was not. Those using the index found information quickly, and learned the vocabulary of terms on the site, making search engine use easier. Most of those not using the index had trouble, but when asked why they didn't consult the index, they said things like "Oh, that would be no use. It's just a site map."

A second stumbling block is that many under-thirty-somethings have never used a book index. Like tables of contents and footnotes, indexes are an endangered information species! For many young people, information gathering is a trip to thousands of sites via Google. How can we get them to appreciate the browsing and finding power of a good index?

Interest Group of ASI. Her resources include several excellent books, notably Website Indexing, by Glenda Brown and Jonathan Jermey and Beyond Book Indexing: How to Get Started in Web Indexing, edited by Diane Brenner and Marilyn Rowland. And she suggests we call the index an A-Z index.

We learned enough from these two books to draft an A-Z index for our CM Pros site. But how will we get visitors to find this great findability tool? We are planning to replace the standard home page search box with a search link and a link to the A-Z index page, where regular search will be available at the top of the page. We hope visitors will first scan down from A to Z, to see what's in the site and what we are calling things.

An A-Z index offers the power to augment even the plainest full-text search engine, but without the usual expense.