RDF - WTF?

Notes by Justin Miller – sorry for typos/omissions


RDF is machine-readable information about information triples: subject-predicate-object anything in a relational DB can be represented in triples

  have a username: “joesmith is a user of X”

SPARQL: query language across resources predicates themselves can, as human knowledge, be described in RDF as well alternatives to using XML for RDF (which turned out to be verbose and bad)

  Turtle

practical applications

  biggest: FOAF (friend of a friend)
      describes social network information
      build it yourself, publish it on your site
      becomes your social network identity
      LiveJournal auto-publishes it for everyone
      WordPress, Blogger, Movable Type as well for years
      vast majority of live RDF today is FOAF

post info about RDF in Drupal

  http://drupal.org/project/rdf
  http://drupal.org/project/fileframework

tool called Zotero - like Evernote

  Firefox plugin
      bookmark a site, tag it (like Delicious)
      also: senses bibliographic info on the page & extracts it for your records
      example: your on an Amazon book page, Zotero saves info into your database

question: why use FOAF vs. some other format?

  it’s already a standard
  tools already exist

N3 allows you to define formalae

  example: X is father of Y, A is cousin of Y, implies X is uncle of A

Thetus: “knowledge discovery software” (based in Portland) interesting application: trust networks as extension of FOAF downside: hard to store a lot of it

  generally you store it in your own format and export RDF (or make it available on demand)
  Billion Triple Challenge: project trying to tackle this challenge

question: anyone looked into using distributed things like CouchDB to store it?

  problem is they are usually key-value, not triples
  someone needs to build a distributed storage DB for this? 
  storage of quads: adding security or lineage info as well

DBpedia: http://en.wikipedia.org/wiki/DBpedia

  trying to take all of Wikipedia’s info and putting it into RDF

question: can we mashup the CIA World Factbook with Wikipedia?

  that’s the dream of RDF, really
  if everything has an absolute URI, then it’s more easily possible

question: what about connecting FOAF info between, say, LJ and Blogger?

  unfortunately a lot of current use is internal to organizations
  but you could write your own FOAF integrating across services and publish that

question: what happens when things change names (say: countries)

  depends on how you define your predicates
      “this country is another name for this country”

question: can you explain the OWL (Web Ontology Language) language?

  http://www.w3.org/TR/owl-features/
  includes mathematical and logical relationships
  example: saying a pine tree is a type of plant implies that plants include trees

also check out Yahoo’s YQL session today at 6:00pm

ww2.txt · Last modified: 2009/10/26 07:12 by akfarrell