From http://www.w3schools.com (Copyright Refsnes Data)
The Semantic Web. A simple example application.
Suppose a semantic web system was built to administer the selling and buying of used cars over the Internet.
The system would contain two main applications:
Let's call the Internet applications for IBA (I Buy Application), and ISA (I Sell Application).
People who want to buy a car could use an IBA application much like this:
I Buy Application (IBA) |
In a "real live" application you would be asked to identify yourself the first time you used it. Your ID would be stored in an RDF (Resource Description Framework) file. Your ID would identify you as a person with name, address, email, and ID number.
When you submitted the query, the application would return a list of cars for sale, and the list could be drilled down and sorted by year, price, location and availability. This information would be returned from a web spider continuously searching the web for RDF files.
People who want to sell a car could use an ISA application much like this:
I Sell Application (ISA) |
When you submitted the form, the application would ask you for more information and store your ID and the information in an RDF file made available to the web.
The RDF file would contain information like:
Your ID: Name, address, email, ID number.
Your selling item: type, model, picture, price, description.
Behind the scene the "ISA" application creates an RDF file with a lot of RDF pointers.
It creates an RDF pointer to a file with information about your person, an RDF pointer to information about Volvo and Volvo models, an RDF pointer to Volvo dealers and resellers, about parts, about prices, and much more.
An RDF pointer is a pointer (actually an URL) to information about things
(like a knowledge database).
The beauty about this is that you don't have to describe yourself, or the car
model. The RDF application will sort it out for you.
Chaos? Standards? What do we need? What are we waiting for?
A standard by W3C, by Microsoft, by Google?
RDF is data about web data - or metadata. Often RDF files describe other RDF files. Will it ever be possible to link all these RDF files together and build a semantic web?
No one knows, but someone will try.
I don't think the semantic web will work all by itself. It will need some help to become a reality.
It is not very likely that you will be able to sell your car just by putting your RDF file on the Internet.
The "ISA" and "IBA" applications above will have to be developed by someone. Someone will have to build a search engine database for all the items, and someone will have to develop a standards for it.
It might be eBay, it might be Microsoft, it might be Google, or someone else. But someone will.
Soon we will see marketplaces based on RDF. And one day you will be able to collect information about almost everything on the web in a standardized RDF format.
It might not be free. You might have to pay for the information, or at least for selling your products.
Publishing information about things on the Internet will be much easier than before. Maybe the RSS language (see our RSS tutorial) will be the solution to some of the problems.
Please go to the next chapter to read more about some semantic web issues.
From http://www.w3schools.com (Copyright Refsnes Data)