Google, the most widely used search engine in the U.S. and among English speakers worldwide, has reached a milestone of sorts now that its index of Internet items has surpassed the 6 billion mark, the company announced Tuesday. Google's index had about 4.5 billion items in August 2003, a spokesman said.
"This represents steady improvement as we keep on adding pages. We want to index all the worthwhile pages out there," said Peter Norvig, director of search quality at the Mountain View, California, company. Along with growing the index, Google also continually refines its ranking algorithms in order to serve up query results that are as relevant as possible to the user's search, he said.
Google is doing a good job of both growing its index and maintaining query-result relevance, an analyst said. "There's no doubt that Google is where it is due to the quality and relevance of its search results," said Graham Mudd, a comScore Networks Inc. analyst. "Continuing to increase the number and types of items a search engine can be used for can only help in this regard."
The 6 billion items include about 4.28 billion Web pages, 880 million images and 845 million Usenet messages, Google said.
A growing category is book-related information pages, including first chapters, reviews and bibliographic information. Google retrieves book-related items through its Google Print service, which is in test mode.
Google's index had about 3.3 billion Web pages in August 2003 and about 400 million images in November 2002, the most recent years in which those items were counted, the spokesman said.