Emergent Semantics

Eric A. Meyer

Complex Spiral Consulting

What Was That Again?

• "Emergent semantics" is a fancy way of saying...
  • Ground-up semantics
  • Grassroots semantics
  • Evolutionary semantics
• The general idea is that nobody acts as director; semantics are created ad-hoc and evolve over time
• What we're talking about is the "lowercase semantic web", as opposed to the Semantic Web

Basic Principles

• Define a microformat that solves a specific problem
• Use or leverage existing XHTML markup structures to express semantics
• Use or leverage existing standards that aren't immediately expressible in XHTML
• A key to this approach is that semantic definitions are human-understandable
  • "Microformats are designed for humans first, machines second"
  • In a like manner, the semantics of everything in XHTML are defined via human languages

Why Take This Approach?

"Students no longer have to deal with muddy sneakers on the trek to McCullough - because two brand-new walking paths are crisscrossing the campus. Adding to the network of pathways that ties the college together, the concrete sidewalks were built over existing paths of dirt that the shoes of students and faculty have plowed over time." —The Middlebury Campus, 28 October 2004

• Put another way: "Pave the cow paths" (Adam Rifkin)
• The semantic web is akin to evolution
• The Semantic Web is akin to Intelligent Design

Who Can Do This?

• Anyone at all, right now, today, without waiting for anyone else's approval
• You want to identify a fairly narrowly defined problem and come up with a simple way to solve it
• To keep standards purists (relatively) happy, a profile at a stable URI will help a lot
• Go see Tantek's talk this afternoon to get the technical details on exactly how you can do this

Okay, How About Some Examples?

• Google's rel="nofollow"
• Creative Commons license-link annotation
• XHTML Friends Network (XFN)
  • Metrolling
• VoteLinks
• hCard
• hCalendar

Metrolling

1. Publish a list of people you met at SXSW, with a link to each person's personal site
2. Add rel="met" to each link

   <a href="http://meyerweb.com/" 
      rel="met">Eric Meyer</a>

3. Ping rubhub.com with your site's URL
4. There is no step 4: you're done!

Success Characteristics

• Solve an immediate problem or fill a need that people are already trying to address in ad-hoc ways
• Keep the solution as simple and understandable as possible
• "Open source" everything so that others can use and build on your work
• New solutions just might emerge from the microformat you've created

Identity Consolidation

• Use of XFN's me value can bring pieces of an identity together

Ways To Cross-Breed and Mutate

• Cross XFN with VoteLinks
  • What do my friends like/dislike? (or, what do Jeffrey Zeldman's friends like/dislike?)
• Cross XFN with hCalendar
  • What are my friends up to in the next few weeks?
• Cross VoteLinks with license annotation
  • What are the most liked/disliked licenses?
• Cross hCalendar with a music-categorization system
  • When are some upcoming shows by klezmer bands?

A More Immediate Example

• Suppose the SXSW Web site used hCalendar to semantically annotate the conference schedules
• Using an hCalendar-to-iCalendar (RFC2445) translation script, it would be possible to subscribe to those schedules
  • ...in iCal or any other calendar program that understands the iCalendar format
  • The translation script would be needed only until a calendar program was updated to understand the hCalendar microformat
• Bingo! Local copies of the Interactive conference schedule, or the band performance schedule, or the movie schedule, or the whole shootin' Platinum-level match...

Next Steps

• Engines are starting to recognize certain rel values; this needs to be expanded to capture all values
• For services that have them, API calls to link relation values should be available
• Scripts to convert from microformats to RFC formats (and back)
• Collections of links to microformatted pages

In Summary

• Microformats designed to add semantic information allow quick, evolutionary enrichment of the Web
• Anyone can do this; there's no fee to join and almost no barrier to entry
• As more microformats emerge, it will be possible to cross-pollinate and get truly human-centric results
• Semantics are already starting to emerge and spread
• The limits are only what problems we can find to solve, and how creative we are in solving them

Thank You!

It's been a pleasure. Questions? Let me know!