Download ppt - Fear of a FOAF planet? (Etech 2004)

Dan Brickley (W3C) - FOAF

FOAF Session logistics

• 4.30-4.55 Danbri- FOAF

• 4.55 Questions

• 5.00-5.10 Edd Dumbill - FOAFBot

• 5.15 Lightning talks (8 x 5 mins)

Fear of a FOAF planet?

Dan Brickley (W3C)[email protected]

O’Reilly Emerging Technology ConferenceFebruary 9-12, 2004


Overview

• What is this FOAF thing?

• What can we do with it?

• Why is it interesting?

• How do its technical and social characteristics relate?

• Where next? Are we ready to go mainstream?


Friend of a Friend (FOAF) basics

• Machine-readable home pages

• FOAF files (pages) and vocabulary (a dictionary of terms)

• RDF markup for “Person”, “mbox”, “homepage”, “workplaceHomepage”, “schoolHomepage”, “knows”, …

• Linked in a (semantic) Web to other FOAF files

• Freeform, loosly constrained, designed to be independently extended without breaking


An example FOAF profile

<foaf:Person>

<foaf:name>Peter Parker</foaf:name>

<foaf:gender>male</foaf:gender>

<foaf:title>Mr</foaf:title>

<foaf:givenname>Peter</foaf:givenname

<foaf:family_name>Parker</foaf:family_name>

<foaf:mbox_sha1sum>cf2fd069302feb63fa7f20bd82</foaf:mbox_sha1sum>

<foaf:homepage rdf:resource="http://www.peterparker.com"/>

<foaf:weblog rdf:resource="http://www.peterparker.com/blog/"/>

<foaf:knows>

<foaf:Person rdf:nodeID="harry">

<foaf:name>Harry Osborn</foaf:name>

<foaf:homepage rdf:resource=“http://www.osborn.com/” />

<rdfs:seeAlso rdf:resource="http://www.osborn.com/harry.rdf"/>

</foaf:Person>

</foaf:knows>

</foaf:Person>


Visualising FOAF: FOAFNaut


Try it and see: the FOAF experiment

• What if machines could read our homepages?

• What do we lose by dumbing down to their level?

• What might search engines evolve into?

• How do we deal with lying, trust, reputation?

Sneaking up on the big hard problems…


Saying things in FOAF:

• “I’m Dan and I work at W3C and I know Libby who works at ILRT and her FOAF profile is [over here] and here are the titles and descriptions of some documents we wrote together.”

• “Here’s my photo like I’d use on my homepage. And here are some other photos, with info on the people and objects depicted in them”

• using FOAF extensions: ” I’m vegetarian. I’m a capricorn. I’m friends with Edd. Here’s my calendar in RDF form. I like the bands Massive Attack and New Order.”


FOAF tech: the acronym view…

• FOAF profiles are RDF/XML documents

• They can say anything (or nothing)

• FOAF vocabulary provides 50+ terms for making simple claims

• FOAF files can use any other RDF terms as well: eg. MusicBrainz, RSS1, Dublin Core, Wordnet, Creative Commons, FOAF Relationship schema, blood types, starsigns, [your idea here]

• The FOAF vocabulary is defined using W3C RDF Schema (RDFS) and the Web Ontology Language (OWL)


Why FOAF uses RDF and OWL

• RDF guarantees freedom of independent extension

• OWL provides fancy data-merging facilities

-> Freedom to say what you like, using any RDF markup you want, and have RDF crawlers merge your FOAF documents with others and know when you’re talking about the same entities.


FOAF recap: low-tech hi-tech

• New kind of Web page for machines (RDF)

• Echoes freedom and flexibility we enjoy in our homepages

• Low-tech solution: like RSS, just a file on your site

• Or published on your behalf by services

• A Web of files describing a Web of people


FOAF on the Web

• Planning for lies, mischief, mistakes

• Importance of who-said-what (PGP, RDFdb, UI)

• Anyone can describe anyone

• Dataset is out of control, distributed

• Legal, privacy and etiquette issues


Lessons from Social Networking tech

• “I want my data back!”

• Each site partially describes our world

• He’s on Friendster; she’s on Orkut…

• Import/export sorely needed

• Friends, fans, ratings: “you have no foaf:friends”

• Allow for fakesters, fun, gaming, personas, secrets and lies.


Where are we today?

• Growing number of self-hosted foaf-a-matic files

• Several services produce and/or consume FOAF profiles (Ecademy, TypePad/Cocolog; LiveJournal and Tribe looming)

• Chatbot, visual, HTML and machine interfaces to aggregated FOAF

• FOAF terms being used in other RDF formats


Styles of FOAF description

• Explicit: FOAF extensions for “friend”, “best friend”, “arch-nemesis”, “cousin”, etc.

• Implicit: work for same organisation, went to same school, co-authored a doc, contribute to same project, appeared in same photos

• FOAF and image description


Applications

• Local: FOAFMobile, BlueFOAF

• Activist: FOAFCorp (fatcat FOAFs), DeanLink, Media annotation

What is FOAF for? -> What is data for?

Anything you can say in RDF/FOAF, you can ask of harvested FOAF data…


Recap and conclusions

• FOAF and RDF as freeform platform for experimentation

• ‘out of control’ by design

• Tech machinery (harvesting, merging) works

• Plenty of room for experimentation, evolution, stylistic variations

• Mainstream? A few lines of code can generate 1000s of new profiles

• Social, legal, privacy, issues need serious attention


Questions and further reading

• http://www.foaf-project.org/

• http://rdfweb.org/ and rdfweb-dev mailing list.