II Web 3.0 explained with a stamp (English version) Part I: the basics Part II: techniques
This is a stamp In 1980 you could buy this stamp for 1 cent Now it’s worth 3 euros This stamp is from the United Kingdom This stamp is used between 1978 - 1981 The picture on the stamp is a PO Box This stamp is designed by John Bryan Dunmore
When a computer understands what data means, it can do intelligent search, reasoning and combining.
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. predicate object subject
With RDFScheme we can define concepts and make simple relations between them.
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.
brother son of mother or father I The rule for calling someone my uncle is that one of my parents has a brother.
<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>
There are a lot of things, that can be described using standard formats.
These things are described with microformats. hCard > contacts hCalendar > events hReview > reviews hResume > resumes XFN > social networks (relation= a friend or colleague)
“I want all the red stamps, designed in Europe, but used in the U.S.A., between 1980 and 1990”
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.
The key to certain data is described in an API (an application programming interface).
An open standard for accessing (authentication) the API is OAuth.