Menlo Park - Google has quietly retooled the closely guarded formula running its internet search engine to give better answers to the increasingly complex questions posed by web surfers.
The overhaul came as part of an update called "Hummingbird" that Google has gradually rolled out in the past month without disclosing the modifications.
The changes could have a major impact on traffic to websites. Hummingbird represents the most dramatic alteration to its search engine since it revised the way it indexes websites three years ago as part of a redesign called "Caffeine", according to Amit Singhal, a company vice president. He estimates that the redesign affects about 90% of the search requests Google gets.
Any reshuffling of Google's search rankings can have sweeping ramifications because they steer so much of the internet's traffic. In the US, Google fields about two of out every three search requests in the US and handles an even larger volume in part of Europe.
Google disclosed the existence of the new search formula on Thursday at an event held in the Menlo Park garage where CEO Larry Page and fellow co-founder Sergey Brin started the company 15 years ago.
Google celebrates its corporate birthday on 27 September each year, even though the company was incorporated a few weeks earlier.
The company is now based in Mountain View, California, at a sprawling complex located about 11km from the home where Page and Brin paid $1 700 per month to rent the garage and a bedroom. The co-founders' landlord was Susan Wojcicki, who is now a top Google executive and Brin's sister-in-law.
Wojcicki sold the home to Google in 2006 and it is now maintained as a monument to the company's humble beginnings.
Google's modifications haven't triggered widespread complaints from other websites, suggesting that the changes haven't resulted in a radical change in the way that Google displays its search rankings.
The Caffeine update spurred a loud outcry because it explicitly sought to weed out websites that tried to trick Google's search engine into believing their content was related to common search requests.
Hummingbird is primarily aimed at giving Google's search engine a better grasp at understanding concepts instead of mere words, Singhal said.
The change needed to be done, Singhal said, because people have become so reliant on Google that they now routinely enter lengthy questions into the search box instead of just a few words related to specific topics.
Just as Page and Brin set out to do when they started Google in a garage, "we want to keep getting better at helping you make the most of your life", Singhal said.