These days, Google seems to be doing everything, everywhere. It takes pictures of your house from outer space, copies rare Sanskrit books in India, charms its way onto Madison Avenue, picks fights with Hollywood and tries to undercut MS's software dominance.

But at its core, Google remains a search engine. And its search pages, blue hyperlinks set against a bland, white background, have made it the most visited, most profitable and arguably the most powerful company on the Internet. Google is the homework helper, navigator and yellow pages for half a billion users, able to find the most improbable needles in the world's largest haystack of information in just the blink of an eye.

Yet however easy it is to wax poetic about the modern day miracle of Google, the site is also among the world's biggest teases. Millions of times a day, users click away from Google, disappointed that they couldn't find the hotel, the recipe or the background of that hot guy. That's why Amit Singhal and hundreds of other Google engineers are constantly tweaking the company's search engine in an elusive quest to close the gap between often and always.

Singhal is the master of what Google calls its ranking algorithm the formulas that decide which Web pages best answer each users question. It is a crucial part of Google's inner sanctum, a department called search quality that the company treats like a state secret. Google rarely allows outsiders to visit the unit, and it has been cautious about allowing Singhal to speak with the news media about the magical, mathematical brew inside the millions of black boxes that power its search engine.

Google values Singhal and his team so highly for the most basic of competitive reasons. It believes that its ability to decrease number of times it leaves searchers disappointed is crucial to fending off ever fiercer attacks from the likes of Yahoo and Microsoft and preserving the tidy advertising gold mine that search represents. "The fundamental value created by Google is the ranking," says John Battelle, the chief executive of Federated Media, a blog ad network, and author of The Search, a book about Google.

Users, of course, don't see the science and the artistry that makes Google's black boxes hum, but the search-quality team makes about a halfdozen major and minor changes a week to the vast nest of mathematical formulas that power the search engine.

These formulas have grown better at reading the minds of users to interpret a very short query. Are the users looking for a job, a purchase or a fact? The formulas can tell that people who type apples are likely to be thinking about fruit, while those who type Apple are mulling computers or iPods. "Search over the last few years has moved from Give me what I typed to Give me what I want," says Singhal. As Google finetunes its search engine, one challenge it faces is sheer scale.

For more details on Google perfect searche visit www.halfvalue.com and www.halfvalue.co.uk

For more information on books visit www.Lookbookstores.com