Yahoo's game of photo tag

Flickr purchase points to radical--and largely untested--theory that could up-end Web search.

Stefanie Olsen Staff writer, CNET News
Stefanie Olsen covers technology and science.
Stefanie Olsen
7 min read
Yahoo's buyout of community photo site Flickr goes well beyond sharing pictures.

The deal, made public Sunday, is the latest in a string of acquisitions in the red-hot online photo-sharing space. But, more importantly, Flickr is a pioneer in a new method for cataloging the Internet that some believe could revolutionize Web search. As a result, Flickr could give Yahoo new competitive tools to take on Google, if it can put Flickr's community-based technology to broader use.

Flickr's trick has been to enlist large numbers of unsupervised volunteers to individually classify files using searchable metadata. Anyone can "tag" files with personal descriptions to help everyone find them more easily. For example, if you want to create an easy way to find a digital photo of Central Park's Christo art project, you might tag it with "NYC," "art" and "orange." Someone who later searches with those keywords will find the photo among the results.


What's new:
Yahoo's buyout of Flickr bolsters a promising new method of cataloging the Internet--and could give the portal giant new competitive tools to take on Google.

Bottom line:
The fevered interest in such technologies comes as companies try to figure out how to satisfy new appetites for consuming information online, so as not to be left behind.

More stories on Flickr

"The democratization of information is the real interesting thing about this," said Bob Rosenschein, CEO of GuruNet, an answer search engine. "They're messy and noisy and they're not always accurate, but they're people talking about real subjects; and in that manner they have tremendous statistical interest when they get to scale. There's a wisdom of the crowd. The most interesting applications are before us."

It's a deceptively simple premise that holds enormous consequences for information management, boosters believe, provided the stars align properly. In addition to Flickr, up-and-coming communities at Wikipedia, Del.icio.us and others have many people pondering the future of free tagging, as some call it.

Given the billions of files available on the Web, tagging has generally been considered unworkable. Flickr has gotten around the problem by recruiting thousands of people to participate for free. Its loose social framework offers a community that lets people discover, quite serendipitously, interesting photos in the collections of strangers. Without a central body of editors controlling the index, the network also can reveal rare insight into cultural zeitgeists from the people using it--for example, users find a collection of Central Park photos taken by locals, rather than professionals.

Interest in tagging comes at a time of great experimentation in search, content distribution and development on the Internet. Companies of all stripes are trying to figure out how to satisfy new appetites for consuming information online, so as not to be left behind.

Finding information in the vast and expanding sea of data online is one of the biggest problems to crack. Creating metadata, or tags, for describing files has long been thought of as a solution for hunting down a range of files on the Web, PCs and intranets, but it has remained an

elusive goal. That could explain why tapping Web users' desire to create addictive services or communities is an attractive solution.

The free tagging philosophy is, "Look, I'm not going to force everybody to use the same tags, and this way the system can grow larger and richer and exhibit emergent phenomenon that its creators didn't think about," said R.V. Guha, co-creator of Really Simple Syndication (RSS) and founder of Epinions.

In a sense, Yahoo is returning to its roots with Flickr. In 1995, Yahoo's co-founders started the site as a way to keep track of their favorite Web pages, and eventually built a massive hierarchical Web directory. Only in the last couple of years has Yahoo put its directory on the backburner in favor of pure search technology. With Flickr, the company is investing in technology that lets people build personalized directories.

Yahoo itself said that digital photography was secondary to its decision to buy Flickr. More important is Flickr's technology and smart founding team, said Yahoo spokeswoman Joanna Stevens.

"Any time you navigate a sea of data, you're going to need something better than search. You need many more dimensions to navigate the data."
--Joshua Schachter, founder, Del.icio.us

"Flickr's strengths are complimentary to Yahoo's goals for creating next-generation services," Stevens said.

Much of Web search originated with directories. The Open Directory, for example, started in the mid-1990s as an open-source project that enlisted volunteers to act as editors, controlling the categorization and hierarchy of new Web pages. But as the project grew, it became unwieldy to force everyone to tag the same way.

Netscape and Excite were among the companies that explored free tagging in the early Internet days. Browser and application makers tested services that let people annotate Web sites and store them to one central location, for example. But nothing caught on because the experiments lacked a critical mass, said Guha, currently a researcher at IBM's Almaden labs.

"Now you have enough people on the Web, and who are in tune to a Web lifestyle, so you can get critical mass to these kind of things," Guha said.

In contrast to the open-source altruism of the Open Directory, Flickr and Web bookmarks manager Del.icio.us have appealed to people's selfish side. With Del.icio.us, people tag Web pages to create their own personalized record so that they can return to them later. People are encouraged to tag files properly so that they can keep their files organized.

"Any time you navigate a sea of data, you're going to need something better than search. You need many more dimensions to navigate the data," said Joshua Schachter, founder of Del.icio.us.

"The tags provide more traction to navigate the world," he added.

Del.icio.us lets people bookmark Web pages they visit and organize them into groups so they can find them later. The site also uses

language associations to recommend the bookmarked Web pages of other users. "It's not about search, it's about discovery and serendipity," Schachter said.

Tapping into group intelligence to create and administer tags could open the door to unknown and surprising applications. If anyone can add their own personal tags to anything, and enough people participate, whole new models for finding and consuming information might emerge. For example, RSS readers that today sort articles by publisher in the future might sort articles by thousands of specific topic areas chosen by readers.

While more traditional efforts to categorize articles are already under way on sites like Topix and Moreover, free tagging could spawn spontaneous categories that no individual might hit on alone. That promises to be more responsive to how people actually look for information, and keep up with changing trends faster, among other things.

"The big question is, are any of these technologies that are capable of improving search, capable of creating the network effect?"
--R.V. Guha, founder, Epinions

One potential flaw is spam. If people seek to misuse tags for personal gain, for example, by labeling files in misleading ways, the system could collapse. On the other hand, there is hope that the system could be self-healing, given that a single tagger or even a small group won't be able to override the will of the majority over the long haul.

Another challenge these communities face is what's called normalizing a taxonomy, or creating consistencies between the language people use to describe their files.

Peter Merholz, a founder at Adaptive Path, a user-experience company, said the happy byproduct of Flickr and other "folksonomies" is that there's this global categorization of information.

"Flickr is valuable because its creators understood the opportunities on the Web in connecting people. It's the same way eBay is all about leveraging the power of the network," Merholz said.

Future applications for free tagging could include news, blogs, Web and enterprise search.

"The future of folksnomies involves meshing these user-generated categorizations with more standardized categorizations, such as the Library of Congress or the Getty Thesaurus of place names, so you could start to connect data to allow more of these associations to be made," Merholz said.

Free tagging could help Web search in a couple of ways. If Yahoo or Google could enlist people to annotate visited Web pages or those which crop up in search results, it could be a valuable voter's guide for them to deliver better results next time.

A key byproduct of free tagging for search would be a visitor loyalty coveted by all the providers. As many researchers point out, the cost to switch search engines is nothing, compared with instant messaging technologies, e-mail, or applications that carry what's called "the network effect." That's why all of the search players are introducing new downloadable tools for PC search.

"The big question is, are any of these technologies that are capable of improving search capable of creating the network effect? If so, then people can't switch out of it," Guha said.

"The key question is," Guha said, "Can Flickr give Yahoo Search the network effect?"