Outline of talk

• Tags and Tagging
• Presentation of Tags
• Tag uses
• Semantics of tagging
• How to go through the tag
• A tiny bit of RDF

Tagging

A lightweight process to describe web content using short words called Tags

The Tagging Process

Combines:

1. The person performing it, the tagger
2. The web resource URI that is being described
3. The date and time of the tagging process
4. The set of tags used - the tagset

Lists of resources for a tag

Popular tags : Tag Clouds

Suggested Tags

Automated analysis of tags

• Clusters
• Interestingness

bristol tag cluster on flickr

Mashups

The Big Assumption: a tag is a primary key

Works well on events such as xtech: Technorati, Planet XTech

Structures

• Geo tagging - lat/long, places
  

  geotagged
  geo:lat=123.456
  geo:long=-123.45
  

• Cell tagging

  celltagged
  cell:network=MyNetwork
  cell:mcc=300
  cell:mnc=400
  cell:lac=5000
  cell:cellid=6000
  

• Blue tagging

  bluetagged
  bt=001234abcdef
  

Hierarchy

cnf on delicious

Grouping

• Bundles in delicious

Whose stuff is tagged?

• Yours on the tagging site
• Other people's on the tagging site
• Anybody's

Whose Tag is it Anyway?

Ultimately, who cares?

Tags are vocabularies per service - tagonomies

So what are the purposes of tagging semantics?

1. For people to understand what some use of a tag means.
2. For computers to gather information about a tag, supporting purpose #1

What does a tag mean to a person?

Ask them? Not scalable.

Look it up in some authority? (dictionary, encyclopedia). Not distributable.

Tagging: Good Things

• Very low barrier to use: just start typing
• Few restrictions on syntax
• Unrestricted word space
• Social description (folksonomy)
• Many takes removes individual tagging wierdness
• Easy to experiment with new ideas for description and structuring

Tagging: Problems

• Formalism problems: mixing types of things, names of things, genres, made up things, ambiguity, synonyms, ...
• Meaning is implicit
• Power curves - nobody explains the long tail tags
• Naive tag mashups mixup meanings
• Syntax problems - stemming, plurals
• tricky to make a short and unique tag

i.e. the usual human-entered metadata problems

Tagging semantics possible solutions

• Microformats: no good hook for software, read only
• Web APIs: for programmers only
• RSS: read only

Tagging Unplugged

• Separate the tag from the service
• Now have a gap: how to go through the tag to find the meaning

Want

• A description
• A community
• A historical record

Answer: Wiki

• A description - the page
• A community - discuss and/or edit
• A historical record - history

Example: raptor tag

top 10 hits for raptor on yahoo search

top 10 hits for raptor on google search

Ambiguity

wiktionary raptor

wikipedia raptor

Wikitag

Easy to create

Can record ambiguity and synonyms/prefered names

Microformat compatible:

• Visible metadata in wiki markup
• Reuse of existing formats

Semantics from Tagging

Tag raptor links to http://en.wikitag.org/wiki/raptor

Edit this page to add the meaning you meant.

Discuss it if you don't understand the term

Add disambiguation

Wiki is not so good at

• Discussion: needs easy to use threaded discussion
• wikipedia rules: e.g NPOV and encyclopedic style
• Centralised :(

The RDF slide

• RSS 1.0
• Atom ( ~= RSS)
• Tags and all their structures
• Semantic Wiki: San Diego on the Semantic MediaWiki

as much or as little as you want

Conclusions

• Tagging is a social process with a gap:
  the place for a community to build the meaning
• Wiki can fill the gap
• RDF can help go through the tag

Thanks

Questions?

bingo

If you have enjoyed this talk...

• http://www.dajobe.org/
• Yahoo! for del.icio.us, flickr and other tagging sites...
• http://planetrdf.com/
• http://en.wikitag.org/