The Semantic Puzzle

Jana Herwig

Web of Data Practitioners Days, 1st Session: Tweaking Turtles [WOD-PD]

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, W3CThe World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web (abbreviated WWW or W3). Founded and currently led by Tim Berners-Lee, the consortium is made up of member organizations which maintain full-time staff for the purpose of working together ..., – 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 BBCThe British Broadcasting Corporation (BBC) is the principal public service broadcaster in the United Kingdom. It is the largest broadcaster in the world with about 23,000 staff. Its global headquarters are located in London and its main responsibility is to provide public service broadcasting in ... in the Programmes ontology project, the aim of which is to provide a simple vocabulary for describing programmes.

Yves’ intro was followed by a TurtleSyntax for RDF that allows RDF graphs to be completely written in a compact and natural text form, with abbreviations for common usage patterns and datatypes. Turtle provides levels of compatibility with the existing N-Triples and Notation 3 formats as well as the triple pattern syntax of the ... 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 N3Notation3 language, of internet Media Type text/n3. Compact and readable alternative to RDF's XML syntax. (http://www.w3.org/DesignIssues/Notation3)Notation3, or N3 as it is more commonly known, is a shorthand non-XML serialization of Resource Description Framework models, designed with ... 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 FOAFhttp://www.foaf-project.org/ 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.talisTalis Group Ltd. is a software company based in Solihull near Birmingham, England that develops a Semantic Web application platform and a suite of applications for the education, research and library sectors. In 2005 Talis was voted one of the top ICT Employers in the United Kingdom..com/stores/wod-pd-sandbox/items/People/> .

people:JanaHerwig a foaf:Person ;
foaf:name “Jana Herwig” ;
foaf:nick “digiom” ;
foaf:homepage <http://digiom.wordpressWordPress is an open source Content Management System (CMS), often used as a blog publishing application, powered by PHP and MySQL. It has many features including a plug-in architecture and a template system. Used by over 12% of the 1,000,000 biggest websites, WordPress is the most popular CMS ....com> ;
owl:sameAsService that helps to find co-references between different data sets. (http://sameas.org) <http://dbtune.org/last-fm/jezobeljones> ;
foaf:knows people:MichaelHausenblas, people:YvesRaimond, people:WolfgangHalb ;
foaf:topic_interest <http://dbpediaDBpedia is a project aiming to extract structured information from the information created as part of the Wikipedia project. This structured information is then made available on the World Wide Web. DBpedia allows users to query relationships and properties associated with Wikipedia resources, ....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/>
DESCRIBE people:JanaHerwig