Search engines can find all manner of online content, much of it inappropriate for children. AOL and Intellext, a maker of contextual search software, now offer an alternative. The two companies on Wednesday introduced the AOL@SCHOOL Desktop Sidebar, which combines the AOL@SCHOOL search engine and its index of more than 48,000 screened educational sites with Intellext's Watson contextual search technology.

A contextual search is one that operates in the background, analyzing the text of open documents to generate topically and conceptually related keywords and then returns search results based on those keywords automatically.

By tying its passive search technology to AOL's kid-friendly search engine, says Al Wasserberger, CEO of Intellext, students and teachers "can get all the information they need without being burdened by a search box and without having all of the unsafe information be part of the search experience."

Unlike other search engines, for example, AOL@SCHOOL's search engine returns no results when the keyword is "porn." But just as Internet content filtering companies generally do not disclose the list of sites they block, AOL does not publish the full list of sites that meet its approval.

"What we say is every single site and all of the data in there has been reviewed by educators," says Mark Stevens, AOL's education director and general manager.

Wasserberger claims that contextual searches deliver more relevant results than keyword searches, citing a study done by Northwestern University, where Watson was developed. "Typically, in the top 10 results, twice as many results are useful results, as subjectively evaluated by the user, compared to search engines," he says.

Citing measurements of information usage associated with company intranets, subscription content, and Internet content, Wasserberger claims use of information sources increases between eight and 30 times when tied to the Watson technology.

AOL@SCHOOL is a 6-year-old online educational portal for K-12 students and teachers. It gets about 1.5 million to 2 million page views and 300,000 to 500,000 unique users a month. It is making the AOL@SCHOOL Desktop Sidebar available at no charge and without ads, but the downloadable software requires a Windows PC.

There's no Mac version at the moment, but that may change eventually. Says Wasserberger, "At some point down the road, we're probably going to be forced to do something with Macs."