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.