MENLO PARK, Calif. - 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 Inc. 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 percent 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 U.S., Google fields about two of out every three search requests in the U.S.