No one knows better than online publishers the importance of matching readers to the right content. "We were getting fed up with Google being able to search our stuff and monetize it better than we could," says Graeme McCracken, COO of Reed Business Search (RB Search), a division of B2B publishing company Reed Elsevier. "We wanted to be as aggressive, innovative and adventurous as Google." Like most publishers with an online presence these days, RB Search also wanted to be content agnostic, offering competitor's content alongside articles from its own journals.

RB Search has developed three taxonomies and a product and service ontology with more than 200,000 core terms, though "none of them are complete," McCracken stresses. "If you ever think you've completed a taxonomy or ontology, you've missed the point because they evolve."

The ontology provides the strict definitions necessary to provide clear guidance as to what content belongs where. For instance, the word pump appears in multiple markets--the pump in an aircraft engine isn't the same as the one in an ice cream machine. "Unless you want taxonomists arguing about whether 'pumps' should be there, and whether that should be a primary node or a secondary node and so forth," you should use an ontology, McCracken says. He cautions, however, that ontologies are "incredibly scary things, because they're dead easy to get wrong."

RB Search uses a homegrown tool called the Harvester that can be pointed at several thousand Web sites that are representative of a particular industry; the tool spots terms it thinks should be in the taxonomy. "The great thing about that is you obtain instant Web relevance and the wisdom of the crowds," McCracken says.

One benefit of having the taxonomies and an ontology in place has been linking Reed's many product offerings. "If we'd tried to do this four years ago, when Reed Business was 900 Web sites across 40 countries with many offices and content management systems, we would have tried to put it all into one SQL database and find a way to index it," a huge task. The taxonomies combined with federated search do the trick.

McCracken says the effort to develop specialized taxonomies and search is paying off. "The user knows we've already disambiguated the content," he says. "The search results are focused on what makes sense to them."