II Web 3.0 explained with a stamp (English version) Part I: the basics Part II: techniques

A presentation from: Freek Bijl (Dutch) blog: Bijlbrand.nl

Web 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 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: The second stamp is called “PO Box” and is from England. It was made in the year: 1992.

=

Red dragon China 1984 PO Box England 1992

We can’t understand words alone. We also need grammar. Online grammar is RDF (Resource Description Framework).

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 father I son of brother

Rules are formulated in SWRL (Semantic Web Rule Language).

x1 x2 x2 x3 x1 x3

So,

Words in XML Grammar in RDF (scheme) and OWL Rules 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 > contacts hCalendar > events hReview > reviews hResume > resumes XFN > 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 stamps A database with countries A database with colors A 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)).

URI URN Red PO Box URL dpobox

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:

Most important references: Presentation JeenBroekstra (Wageningen UR)