Good morning from Vienna:) The Web of Data Practitioners Days really kicked off with a bang today – with Michael Hausenblas doing a strip! Only to expose the Semantic Web t-shirt he wore underneath his smart suit and tie, of course, but he really got the attention of attendees at 9:15 in the morning:)
First session – Web of Data 101 by Yves Raimond and Keith Alexander – explained the implications of the move from a Web of Documents to a Web of Data: With the Semantic Web architecture, data can be made explicit on the web. Data here means not only data contained in documents, but data describing persons, cities, bands, events, finally arriving at the “Web of Things” (see also this presentation by Dave Raggett, W3C, – PDF 2,7 MB). The Web of Data wouldn’t be a Web if the data weren’t interlinked – here is an overview of the principles of Linked Data:
- always use URIs as names for things
- more specifically, use HTTP URIs so that people can look up those names on the web
- when someone looks up an URI, provide useful RDF information (RDF is the data model used for data on the web of data)
- include RDF statements that link to other URI (otherwise it wouldn’t be a web).
Please also watch out for what is already happening and is going to happen in the future on www.bbc.co.uk/music/beta. This beta site is powered by MusicBrainz, the open content music database that is also part of the Linked Data cloud. Yves is collaborating with the BBC in the Programmes ontology project, the aim of which is to provide a simple vocabulary for describing programmes.
Yves’ intro was followed by a Turtle hacking session led by Keith Alexander. Turtle is a serialisation format for RDF, i.e. a format in which you can write RDF statements. The Turtle session is documented here on Keith’s Talis website. Even though I copied and pasted most of the code, I didn’t manage to produce a piece of valid code in N3 right away (i.e. not valid according to this validator). It only worked after I had removed the statements about who I know or what I am interested in – without these connections, what remains is a bit boring, I guess. But this looks like I managed to post at least something to the test store!
EDIT: Problem was that I had terminated the statements to soon, with a dot where a semicolon should have been; the demo didn’t allow me to overwrite the first post to the store, but here is my FOAF self-description in Turtle:
@prefix foaf:<http://xmlns.com/foaf/0.1/> .
@prefix owl:<http://www.w3.org/2002/07/owl#> .
@prefix people:<http://api.talis.com/stores/wod-pd-sandbox/items/People/> .
people:JanaHerwig a foaf:Person ;
foaf:name “Jana Herwig” ;
foaf:nick “digiom” ;
foaf:homepage <http://digiom.wordpress.com> ;
owl:sameAs <http://dbtune.org/last-fm/jezobeljones> ;
foaf:knows people:MichaelHausenblas, people:YvesRaimond, people:WolfgangHalb ;
foaf:topic_interest <http://dbpedia.org/resource/Semantic_Web>, <http://dbpedia.org/resource/Web>, <http://dbpedia.org/resource/Popular_Culture>, <http://dbpedia.org/resource/Lolcat>.
Achieved with zero Semantic coding skills – the Web of Data cannot be so hard to achieve:)
EDIT: Did do the update, too – just posted my first SPARQL query to this endpoint. Are the results going to be preserved in this link? Here is the query “by foot”:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX people: <http://api.talis.com/stores/wod-pd-sandbox/items/People/>