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