AltaVista Co yesterday unveiled a handful of upgrades to its web search engine to compete in an increasingly competitive market where it has lost much of its early lead. The company, a CMGI Inc subsidiary, introduced Prisma, a feature that allows users to drill down into related terms to refine their search queries.

The Palo Alto, California-based company said Prisma searches the top 50 sites returned for any given query to find the top 12 related terms. A search for "Buffy", brings back "Vampire Slayer" and "Fan Fiction", for example. Clicking on one of the terms adds that term to the original query and presents more refined results.

Prisma looks a little like core features from emerging rivals such as Teoma (part of Ask Jeeves Inc) and WiseNut (part of LookSmart Ltd), though in a random sampling AltaVista's drilldown options seemed to be more useful than the competition's, which use convoluted link analysis to find related words and occasionally bring back garbage.

In addition, AltaVista's feature has a secondary option that allows the related search to replace the original query with one click. So users searching for "Apple" may find the related term "Macintosh" more useful a query. Prisma offers two levels of drilldown before a user has to click on a link.

A further upgrade involves the automatic inference of the AND operand in searches involving more than one keyword. Previously, a user may have had to specify they wanted to see "Britney AND music" to avoid getting pages that contained the term "music" but not "Britney".

It's arguable that the company has neglected its web search engine - once regarded as the best on the web - over the last couple of years, as it focused on its enterprise software division in the face of the dot-com bust and extensive restructuring. Prisma looks a little like catch-up, and offers little that was not already possible with AltaVista's featured but complex Boolean search feature, which has yet to be bettered.

AltaVista also announced yesterday that it has increased the size of its index to 1.1 billion items. This is a little less than half the size of the leading search engines. Google claims 2.07 billion items, and Fast Search & Transfer ASA's AllTheWeb.com claims 2.09 billion pages. AltaVista says its multimedia index has 140 million images, videos and image files in it, compared to Google's 330 million images.

In related news yesterday, AltaVista competitor Google Inc announced that AT&T Corp has selected its web search service to feature prominently on the portal associated with its WorldNet consumer internet access service. As with similar recent deals, Google has also sold its paid-position sponsored links service into the account. Google counts Yahoo, AOL and EarthLink among its clients.

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