Menlo Park, California: Facebook is an excellent tool for certain kinds of social interaction. With a couple of clicks, you can share a cute photo of your newborn baby. You can pop over to the page of a college buddy and find out where he lives now and whether he is a fan of Mad Men.
But just try finding that photo of Mom and Dad in front of the Eiffel Tower during their 2008 trip to Paris, or the name of that lovely bistro nearby that they mentioned in a status update. Odds are, you would have to plow through a lot of old posts and photos to dig out that information, if you could find it at all.
Now, Facebook is trying to make it easier to find that lost photo or restaurant recommendation and unearth other information buried within your social network with a tool it calls Graph Search.
On Monday, the company rolled out the feature to its several hundred million users in the US and to others who use the American English version of the site. Other languages will follow.
Developing a sophisticated search feature is vital to Facebook’s long-term success, both to deepen users’ engagement and to make it more appealing to advertisers.
Experts say Facebook’s technical achievement so far is impressive. Privacy could still be an issue, however, as more user data becomes easily accessible. Also, the feature is dependent on Facebook users volunteering more information about their likes and dislikes.
Ever since Facebook released an early version of the tool in January, the development team has been observing and listening to millions of testers and making improvements. “We launched it early, when it still was in a pretty raw state,” Lars Rasmussen, the engineering director of the project, acknowledged in a recent interview.
Early on, Rasmussen said, users had trouble even finding the search box, which was blue and melded into the border at the top of every Facebook page. The team eventually made the box white and used words to explicitly describe its purpose.
The tool also has struggled to understand how people actually use language.
For example, typing in “surfers who live in Santa Cruz” confounded the search engine, which was tuned to recognize the phrase “people who like to surf” but not synonyms like surfers or “people who like surfing,” said Loren Cheng, who leads the team of linguists who are working to refine the tool’s natural language capabilities.
The engineers also had to adapt the algorithms to consider the many ways people express interest in a topic.
For example, Rasmussen, a ballet fan, said that when he looked for “friends who like ballet,” only two popped up. But many more friends had liked the pages of individual ballet companies. So the search engine now takes into account related pages when assessing whether users like a topic.
Facebook’s Graph Search is still a work in progress, as company officials are quick to acknowledge. Its recognition of synonyms and related topics is spotty. It cannot yet find information in status updates, a top request from users. It does not yet incorporate information from third-party apps like Yelp or Instagram, which is owned by Facebook. And the new search tool is not available on Facebook’s mobile apps, which are increasingly the way that people use the service.
But Facebook believes it is now good enough for wide release. And despite the tool’s limitations, technologists praised the company’s work.
“There is a near infinite variety of ways to say anything in English or in any other language,” said Nick Cassimatis, an associate professor at Rensselaer Polytechnic Institute and a co-founder of SkyPhrase, a start-up working on similar natural-language search technology. “They are trying to memorize all the ways of saying something.”
Unlike Google’s familiar search engine, which typically takes the keywords entered into a search box and matches them to the most relevant Web pages that contain them, Facebook’s search looks primarily at structured data. That means the company analyses the virtual check boxes people fill out on the site, like movie pages they have liked, restaurants they have checked into, the city they live in and their relationship status.
That creates particular challenges.
“We don’t go through and ‘like’ all the things that we really like,” said Danny Sullivan, founding editor of Search Engine Land and a longtime observer of the industry. “And if you don’t do that, the database is minimal.”
Privacy is another complication. The company promises that Graph Search will show only information the searcher would normally be allowed to see under the privacy settings defined by the person who posted the data. So a search for Christians in San Francisco who like to knit won’t pull up everyone who fits that profile, only those who have decided to publicly disclose their religion, love of knitting and location. As Graph Search becomes widely available, Facebook users might be surprised at what information about themselves shows up in searches that others do, especially if old items were posted with looser privacy restrictions.
Finally, the company must deal with the flood of new data coming in. It said its 1.1 billion global users posted 3.3 million new items every minute in May. If the firm does make it easy for users to sift through all of that information, it could open a new era in search. ©2013/THE NEW YORK TIMES