building a semantic website

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A simple tutorial introducing methods and technologies used to build semantic websites, and why you should want to.

TRANSCRIPT

  • 1. Build a semantic web websitehttp://scienceforseo.blogspot.com

2. What is the semantic web?

  • It is a very powerful way to access information on theweb.
    • It is a web of data where everything is linked in.
    • It allows applications to talk to each other, reusing and sharing this data.
    • The data is shared via a common web architecture (e.g.URI's)
    • Relationships in the data are created by tools and some are also created manually.
    • Thus machines can interact with data and humans can access far more accurate and useful data.

3. How is it useful in practise?

  • You could not only access your photos, calendar, diary and so on, but also have relevant photos appear when you look at a specific event in your calendar
  • You could be writing a document and you could ask for other documents that you want to reference without having to look for them.
  • You can do a search and share that data with a friend or colleague, and relevant additional information that is relevant would be available to you both.

4. Why does this matter to my site?

  • Without semantic mark-up, databases, ontologies and so on, your site cannot be picked up by engines like Google and others able to use semantic elements.
  • Your site would then not get the visibility it deserves and could have.
  • Your competitors may have prepped their site already and although you show #1 in the rankings, they are have more pulling power than you do.
  • Mozillaare deploying a whole host of RDF tools

5. How does it work?

  • Instead of using hyperlinks to link documents, the SW can be linked to any 2 resources (not just one document).This is achieved using RDF, OWL, SKOS.
  • These allow you to describe documents, resources, people, categories, anything you like, in a machine readable way.
  • RDF also provides an XML based syntax.
  • These are linked by URI's

6. Example RDF

  • It's about Bob Dylan (from W3C schools)
  • http://www.w3schools.com/rdf/rdf_example.asp

7. Example OWL

  • This the famous Koala Bear example - Wine is
  • very thorough and a good tutorial though.

8. Example SKOS

  • Single knowledge organisation system reference
  • FromXML.com

9. GRDDL

  • It stands for Gleaning Resource Descriptions from Dialects of Language.
  • It allows RDF triples to be extracted from XML documents like XHTML which is often used as an example.
  • GRDDL transformations can be attached to XML documents.
  • The output of that is an RDF representation of the data and it can be queried using SPARQL (don't worry, it's covered a few slides on)
  • There is a full example of GRDDL atW3C .

10. RDFa

  • It stands for Resource Description Framework- in-attributes and it extends XHTML.
  • It uses attributes from XHTML to allow you to tag everything up for semantic stuff.
  • It extracts RDF triples using a mapping method.
  • It allows for the data to be easily visible to humans and to machines, as the HTML and RDF are self-contained (separate).
  • Data is reusable. Non-duplicated, and each site can have its own standards.
  • SeeW3Cfor a good primer and examples.

11. URI's

  • URIs are the Nouns (Uniform Resource Identifier)
  • HTTP is the Verbs (GET, PUT, POST)
  • The URI as you may know is used for mailto:, http: and so on (used to be called URL).
  • They are used to access representations of resources.
  • URIs give RDF identifiers so statements can be made about statements.

12. Example URI

  • In N-Triple format (Plain text MIME format represents the correct answers for parsing RDF)
    • In URI format (the RDF is appended):
    • rdfuri:%3cBananas%3e%20%3are%3e%20%3cyellow%3e%20
    • There is a full list of official URI schemes to usehere .

13. SPARQL

  • It stands for SPARQL Protocol And RDF Query Language pronounced Sparkle.
  • It's like an SQL language especially made for the SW.
  • It's based on the RDF framework and uses WSDL (Web Services Description Language)
  • It has a query language, access protocol and the RDF data model.
  • It's basically a search engine for the SW.

14. so...

  • You can retrieve data, as you would in a normal or even massive database using a relatively small application from the entire web.
  • You can query all comments, RSS feeds, images, FOAF, everything you might want want to all at the same time.
  • It's easy to code and very short too, even though it is very powerful

15. SPARQL example

  • This is fromWiki Musicontology see there for more examples.

16. FOAF

  • This stands for Friend Of A Friend.
  • It allows you to create a file that sites with your website.
  • It is a machine readable social network where each profile has an individual URI.
  • In the FOAF file you state who you are connected to, which projects, any publications you've written, anything at all.
  • Their official site ishere .
  • Also see Libby's bloghere .

17. Example FOAF

  • The vocab specification ishere , example fromxml.com

18. There are tools to help you

  • Converter Tools:
    • -TopBraid(available as Eclipse Plugin)
    • - Put yourPalm OS datainto RDF
    • -MindSwapCSV to RDF
    • -FlickCurl Flicker to RDF
    • - XML.com: XML to RDF
    • - Manchester UniOwl syntax converter

19. And more...

  • Development environments:
      • -Protegeopensource java tool
      • -JenaJava Famework
      • - TheRDFeditor
      • -Altovafrom Semanticworks
      • -RDFein Python
      • -SimplisticRDF editor

20. And more...

  • RDF Generators:
    • -KWARCRDF extractor
    • -OpenCalais superb
    • -Triplifyplugin for applications
    • -Zemanta I love it
    • -FOAF-Visualizer to work with FOAF
    • -Foaf-o-maticto generate FOAF files
    • -Ruby RDF generator for Ruby fans

21. And more...

  • Extras:
    • -MOAT meaning of a tag
    • -Amalgram good for linguists
    • -AllegrographRDF store
    • -BrownSauceRDF browser
    • -Conceptool- check your ontologies
    • -Fact++ is an OWL reasoner
    • -Addsemantics to Excel
    • -IBM semantic Layered Resource Platform
    • And there are many many more...

22. Tips

  • To put RDF into (X)HTML use RDFa which has an XHTML 1.1 module.
  • Use an RDF data browser to see RDF on the web such asDiscoorOpenLink RDF or aFirefox extension .
  • PingtheSemanticWebis a good source of RDF all ready made and so isSchemaWeb
  • Oh andDapperwill semantify your site :)

23. Links

  • Book: The explorer's guide to the semantic web
  • Book: ASemantic web guide
  • Book: Semantic web for the working ontologist
  • Book: The explorers guide to the semantic web
  • Tim Berners-Lee Why RDF is different to XML
  • RDF core working group
  • IBM:Planning a semantic website
  • Stanford:Semantic website clustering