IIWeb 3.0explained with a stamp(English version)
Part I: the basics
Part II: techniques
A presentation from: Freek Bijl(Dutch) blog: Bijlbrand.nl
Web 3.0 - the semantic web - is about the meaning of data.
This is a stamp
This stamp is from the United Kingdom
This stamp is designed by John Bryan Dunmore
In 1980 you could buy this stamp for 1 cent
Now it’s worth 3 euros
This stamp is used between 1978 - 1981
The picture on the stamp is a PO Box
Why do we want to add meaning to
data ?
When a computer understands what data
means, it can do intelligent search,
reasoning and combining.
This makes our live more easy.
The next technologies are used to make a
more semantic web…
RDF XML URI SPARQL XDI XRI SWRL XFN OWL
API OAUTH
!Complicated
An explanation with a stamp collection.
Meaning is about understanding. To
understand we need a language. A language
starts with words.
Things mean something in words. Online, we describe things with
XML.
This is my stamp collection
The first stamp is called “Red dragon” and is from China. It was made in the year: 1984.
The second stamp is called “PO Box” and is from England. It was made in the year: 1992.< .. etc >
=
<?xml version="1.0" encoding="ISO-8859-1"?><collection name=”My stamp collection"> <stamp> <title>Red dragon</title> <country>China</country> <year>1984</year> </stamp> <stamp> <title>PO Box</title> <country>England</country> <year>1992</year> </stamp></collection>
We can’t understand words alone. We also need
grammar. Online grammar is RDF (Resource
Description Framework).
This stamp is from England.
This stamp is from England.subject
predicate
object
With RDF Scheme we can define
concepts and make simple relations between them.
This stamp is from England,
hence from Europe.
But, RDF scheme is limited. A language needs more
expression and logic to make good reasoning possible.
That’s why OWL (The Web Ontology Language) was
invented.
Finally, to reason you need rules.
I got this stamp from my uncle.
The rule for calling someone my uncle is that one of my parents has a brother.
mother or fatherIson of brother
Rules are formulated in SWRL (Semantic
Web Rule Language).
<ruleml:imp> <ruleml:_rlab ruleml:href="#example1"/> <ruleml:_body> <swrlx:individualPropertyAtom swrlx:property="hasParent"> <ruleml:var>x1</ruleml:var> <ruleml:var>x2</ruleml:var> </swrlx:individualPropertyAtom> <swrlx:individualPropertyAtom swrlx:property="hasBrother"> <ruleml:var>x2</ruleml:var> <ruleml:var>x3</ruleml:var> </swrlx:individualPropertyAtom> </ruleml:_body> <ruleml:_head> <swrlx:individualPropertyAtom swrlx:property="hasUncle"> <ruleml:var>x1</ruleml:var> <ruleml:var>x3</ruleml:var> </swrlx:individualPropertyAtom> </ruleml:_head> </ruleml:imp>
So,
Words in XMLGrammar in RDF (scheme) and OWLRules in SWRL
There are a lot of things, that can be
described using standard formats.
For example: contact information.
These things are described with microformats.
hCard > contactshCalendar > eventshReview > reviewshResume > resumesXFN > social networks (relation= a friend or
colleague)
Suppose, I want to search for a specific stamp.
“I want all the red stamps, designed in Europe, but
used in the U.S.A., between 1980 and 1990”
We can use SPARQL (Protocol
and RDF Query Language).
Because the web is decentralized and data is in many places, not only language is important.
Exchange of data between different machines is key.
A database with stampsA database with countriesA database with colorsA database with stamp traders
To make a connection a machine needs a source. For this, we use resource identifiers. Best known
resource identifier is the URI (which consists of a name (urn) and a
location (url)).
Because URI’s have international limitations and the need for data-exchange
between machines is rapidly growing there is a successor:
XRI (Extensible Resource Identifier)
There is a standard for sharing, linking and synchronizing data.
This standard is called XDI (XRI Data Interchange).
With all this I am capable of using the power of all different data resources on the
web.
But…
Data is protected. We need consent and a key to gain acces.
The key to certain data is described in an API (an
application programming interface).
An open standard for accessing (authentication)
the API is OAuth.
So,
RDF XML URI SPARQL XDI XRI SWRL XFN OWL
API OAUTH
… are now words with a meaning for you !
.end
My (Dutch) blog: http://www.bijlbrand.nl
Most important references:
• http://en.wikipedia.org/• Presentation JeenBroekstra (Wageningen UR)