What is the scent of information? What does your sense of smell have to do with the findability of your Web pages?

Nearly ten years ago, Peter Pirolli and Stuart Card, information scientists at Xerox PARC, compared humans seeking information on computers and the Web to animals foraging in the wild for food. They equated clues that lead animals to food (usually their noses picking up a scent) to clues in a Web page that might lead to what they called information patches. "Informavores," they called us content foragers.

In recent years, their idea of Information Scent has been popularized and specific techniques for improving Information Scent reported, most notably by Jared Spool of User Interface Engineering. The tenth anniversary of Spool's User Interface Conference was held in Cambridge last month, just a week before the User Experience 2005 conference in Boston by the world's most famous usability experts, Jakob Nielsen and Donald Norman of the Nielsen/Norman Group.

Your fearless reporter attended both of these conferences trying to sniff out things that could help visitors find content on your sites, especially tactics and tools that could also improve your search engine rankings. Information Scent stood head and nostrils above the rest as a leading new tool.

"Information foraging is the most important concept to emerge from Human-Computer Interaction research since 1993," according to Nielsen. And "information foraging's most famous concept is Information Scent." Spool agrees. His UIE Report, "Designing for the Scent of Information," includes results from several user research sessions that show how easily scent can be lost or found in a Web page. He helps you identify the "trigger words" that give off scent and how they need to be placed in surprisingly long hyperlinks--seven to twelve words long--to help browsers follow their noses to your content.

Do Your Links Stink?
Short links, like those typically in the navigation, do not give off scent, and have led to a phenomenon called "navigation blindness" (maybe because navigation anosmia isn't as catchy.) Short links do work well if augmented by a descriptive phrase, or by sublinks to other subcategories. This can be seen in the famous look of the Yahoo! portal and similar DMOZ and Google directories.

Information Scent enables findability and search engine optimization. Put yourself in the position of a search engine designer, who does everything they can to make their search robots read pages the way humans read them. Thus, for the most part, they ignore metadata. Search engines look for words in the context area, and tend to deemphasize words in the global top navigation and the local left navigation, which probably appear on every site page (and as such, don't help the search engine to discriminate).

Ambient Findability
One highlight of the two user conferences was that each included a great bookstore near the registration desk, assembled by Quantum Books. The most exciting book at both conferences was the new Ambient Findability, by Peter Morville, who co-authored with Lou Rosenfeld the best-selling Information Architecture for the World Wide Web. Filled with engaging descriptions of how new technology is making everything,--including physical objects and people, as well as content--more findable, and lavished with dozens of color illustrations (O'Reilly's first color book in some time), Ambient Findability is a must read to learn how our world is changing and how we must ourselves change along with it.

Morville's most staggering vision is one of a world where many of us get an implanted RFID chip that allows us to be found and displayed on a Web page (like Google Earth). Obvious benefactors would be wandering Alzheimer's patients, and many zealous parents would want to better track their children, as they do now with Wherify bracelets and cell phones. Morville also describes a current RFID-human implementation: beach-goers in Barcelona, Spain can elect to have an RFID chip injected into their arm. This way, they can pay their way via transponders like those that whiz you through turnpike tolls--dispensing with wallets, purses, and credit cards that might clash with sexy bathing suits.

Until your Web pages have the same unique ID for virtual objects that the RFID provides for physical objects, your best bet is to learn how to enhance the Information Scent of your Web pages. The nose knows.