Google has been stunningly adept at devising computer algorithms to help people search the Internet. But when it comes to building features for social networking, the company has been much less effective.
And changing that is one of the company's biggest business challenges these days.
Google depends on having its finger on the pulse of the entire Internet, and maintaining its status as the primary entree to the Web. But as people spend more time on closed social networks like Facebook, where much of the data they share is off limits to search engines, Google risks losing the competition for Web users' time, details of their lives and, ultimately, advertising.
"Google's made a lot of money helping people make decisions using search engines, but more and more people are turning to social outlets to make decisions," said Charlene Li, founder of Altimeter Group, a technology research and advisory firm. "And whenever people make decisions, there's money involved."
Google has been trying to create social components, most recently with Buzz, a service that gives Gmail users the ability to share status updates, photos and videos. But that, and earlier efforts, have not been hugely popular.
Now the company will try again, with tools to be unveiled this fall, said Eric E Schmidt, Google's chief executive. Although the details remain murky, Mr Schmidt and other Google officials sketched a broad outline of their plans in recent interviews.
Some of the tools are still being developed, they said; others will add features to existing products, like search, e-mail, maps, photos, video and ads.
The company plans to "take Google's core products and add a social component, to make the core products even better," Mr Schmidt said.
But some wonder whether Google understands enough about social connections to create the tools people want to use.
"Google's culture is very much based on the power of the algorithm, and it's very difficult to algorithm social interaction," Ms Li said.
For example, the introduction of Buzz in February caused a wave of criticism from privacy advocates and everyday users, because it automatically included users' e-mail contacts in their Buzz network. Google quickly changed the service so that it suggested friends instead of automatically connecting them.
Before Buzz's release to the public, it was tested only by Google employees.
"There is some belief at Google that their DNA is not perfectly suited to build social products, and it's a quite controversial topic internally," said a person who has worked on Google's social products who would speak only on the condition of anonymity.
"The part of social that's about stalking people, sharing photos, looking cool -- it's mentally foreign to engineers," the person said. "All those little details are subtle and sometimes missed, especially by technical people who are brought up in a very utilitarian company."
Google has a social network, Orkut, but that never took off in the United States, although it is popular in Brazil and India. There are also Google profiles, which let people link Google to LinkedIn and Twitter, for example, so that information their friends have published online can appear in search results. Only a small percentage of Google users have created these profiles.
And as Facebook gains in popularity, it grows as a threat. Google sites, including the search engine and YouTube, get more unique visitors than Facebook. But in August, for the first time, people spent more time on Facebook than on Google sites, according to comScore, the Web analytics firm.
Some people are beginning to turn to their friends on Facebook for information for which they had used Google, like asking for recommendations on the best sushi or baby sitter.
Through a new partnership with Microsoft, an investor in Facebook, the things your friends like on Facebook can show up in the search results from Bing, Microsoft's search engine.
The threat goes straight to the bottom line, too. Facebook is increasing its sales of display ads with images, which Google is counting on as its next big business.
Google has assembled a team of engineers to work on social networking, led by two executives who worked on Buzz -- Vic Gundotra, vice president for engineering responsible for mobile applications, and Bradley Horowitz, a vice president for product management overseeing Google Apps.
"Google, as part of our mission to organize the world's information, also needs to organize and make it very useful for you to see the interactions of your friends, to participate with them and benefit," Mr Gundotra said.
The company has also been piecing together a puzzle of social networking companies, technologies and engineers. It acquired Slide and Jambool, which made apps and virtual goods and currency for social networks, and Angstro, which built tools to exchange information among social services. This year, it bought Aardvark, to which users can post questions that are answered by individuals, and invested in the gaming company Zynga.
But the new project will not include a big gaming element, despite previous reports, said a person who has worked on the products.
"Google's a pretty serious place," Mr Schmidt said. "It's hard to see how we could end up as becoming a significant gaming or entertainment source. It's much more likely that we would become an infrastructure for those sorts of things."
Whatever Google does, its officials said, it would not build a Facebook reproduction that requires users to re-enter all their personal and social data. "I think that there is social networking fatigue," Mr Horowitz said.
The stakes are high, because people increasingly go to friends on other sites, like Yelp, Facebook or Twitter, with their search questions. For example, Ms Li of the research firm recently asked her Twitter friends where to shop for clothes for her middle schooler and got answers from people who know her and her child.
"In the past I could have gone to Google and that would have been a huge advertising opportunity for Gap or American Eagle, but Google never had a chance to see my intention," she said.
The potential for social information reaches beyond search. Facebook's most popular feature is photo sharing and tagging friends in pictures. Picasa, Google's photo-sharing service, is not nearly as social.
Ads also have the potential to be social, when people share and comment on them. Neal Mohan, the Google vice president in charge of display ads, said that by 2015, three-quarters of display ads will be social. But Facebook already allows users to do this. Knowing the information people share on social networks -- like their age, gender and the restaurants and musicians they like -- could also help Google direct ads more effectively.
Larry Yu, a Facebook spokesman, said his company expected competitors large and small to emerge but was focused on building a valuable service. Privately, though, Facebook executives have said that their biggest worry is that Google will prioritize a Google profile page over a Facebook page in search results.