5/17/20151 FOAF

5/17/20152 Introduction Metadata is data about data The terms refer to data used to identify, describe, or locate information resources Metadata helps manage and use large collections of information Library card catalogs are example of metadata

5/17/20153 Popular Schemas Dublin Core FOAF FRBR Creative Commons SKOS Geo See

5/17/20154 FOAF: Friend of a friend “The Friend of a Friend (FOAF) project is about creating a Web of machine- readable homepages describing people, the links between them and the things they create and do. ” ( Annotation vocabulary for linking semantic information about people to achieve a social network Everybody can provide/link his/her own FoaF file on his/her own webpage. Related to the success of “social networks”: friendster, orkut, ryze, LinkedIn etc. But: these use disclosed applications/databases/portals instead whereas Foaf is intended to work decentralized and based on RDF. Reference: FOAF Vocabulary Specification 0.91:

5/17/20155 FOAF Vocabulary: See details at

5/17/20156 Basic example Dan Brickley fb0e6289f92815fc210f9e c252e

5/17/20157 FOAF: Basic Idea To a computer, the Web is a flat, boring world, devoid of meaning. This is a pity, as in fact documents on the Web describe real objects and imaginary concepts, and give particular relationships between them. For example, a document might describe a person. The title document to a house describes a house and also the ownership relation with a person. Adding semantics to the Web involves two things: allowing documents which have information in machine-readable forms, and allowing links to be created with relationship values. Only when we have this extra level of semantics will we be able to use computer power to help us exploit the information to a greater extent than our own reading. - Tim Berners-Lee "W3 future directions" keynote, 1st World Wide Web Conference Geneva, May 1994

5/17/20158 FOAF: Basic Idea FOAF aims to create a linked information system about people, groups, companies and other kinds of thing. If people publish information in FOAF document format, machines will be able to make use of that information. If those files contain “see also” references to other such documents in the Web, we will have a machine-friendly version of today’s hypertext web FOAF documents are usually represented in RDF.

5/17/20159 FOAF basic concepts foaf:Agent An agent (eg., person, group, software or physical artifact) Subclass: foaf:Person, foaf:Organization, foaf:Group foaf:Document Sublcass: foaf:Image foaf:Person A person foaf:Project A project

5/17/ FOAF basic properties foaf:family_name foaf:firstName foaf:homepage foaf:knows A person known by this person foaf:mbox foaf:mbox_sha1sum foaf:title Personal title (Mr, Mrs, Ms, Dr, etc.)

5/17/ Create your own FOAF ldodds.co m/foaf/foaf- a-matic Fill in the detail of yourself It will create FOAF in RDF <rdf:RDF xmlns:rdf=" xmlns:rdfs=" xmlns:foaf=" xmlns:admin=" Ying Ding Mrs. Ying Ding f782acba4fc1c1bbecefc41fe2696fa62a84dfe5 Stefan Decker 1bc1f862b688a45b7e0c8d4a8467c23177c53fad Ioan Toma 1e9f327c5c745341ad aa

5/17/ Publish your FOAF description Save your FOAF RDF file into your website somewhere and name it usually as “foaf.rdf”

FOAF Example in RDF/XML <rdf:RDF xmlns:rdf=" xmlns:foaf=" John Breslin Stefan Decker foaf:knows foaf:Person John Breslin rdf:type foaf:name foaf:Person Stefan Decker rdf:type foaf:name foaf:mbox

5/17/ FOAF Conclusions Vocabulary for machine-processable personal homepages currently some preliminary tools available not yet as successful as social networks such as friendster, which use proprietary central data advantage of foaf: decentralized, could serve as exchange format between those existing networks and exists on its own