23 Things: 5. Read about the Semantic Web

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Now that we have a bit of an idea of what “Web 2.0” is, some people have begun to speculate about what Web 3.0 might consist of. Many accept that it will focus on the Semantic Web, a concept introduced by the inventor of the web, Sir Tim Berners-Lee and explained in his book Weaving the Web: The Original Design and Ultimate Destiny of the World Wide Web (2000).

The word "semantic" refers to the meaning of text, and the "Semantic Web" refers to the idea of drawing meaning from the information on the web.

The web as it currently stands consists largely of free-form text as well as images, links, interactive forms and more. Automatic machines such as search engines can do a good job of grabbing and storing this text and these links, so that we may use keywords to find information. However, these machines are simply looking for word matches. They cannot logically understand the meaning of the text on the web and draw logical conclusions from it.

If we use standard file formats which mean something to computers rather than humans, then machines would be able to do something more intelligent with that data. Such file formats wouldn't contain text for humans to read and understand, but data for computers to understand: information on "people", "dates", "events", "places" and other things.

Let's say we wanted to find the answer to a complex question like, "what was the weather like in Melbourne on the opening day of the Seoul Olympics?" Search engines are particularly bad at finding such data, because it would typically involve looking up information from more than one source and understanding how it relates together.

If there existed a standard computer based format for expressing dates, events, locations, and weather, however, and there were websites which provided information in this format, then a search engine or other computer based process may be able to find the answer to the above question.

While the Semantic Web as described by Berners-Lee has not yet been realised oon a large scale, its concepts have been used in the formation of a set of standards, such as RDF (Resource Description Framework), a file format which describes what data means.

Some, such as blogger Cory Doctorow (Walmsley, 2008) argue that it could never be realised on a large scale due to the unreliability of metadata. He suggests that getting people to create data that it is both in a consistent format and free from errors is asking too much of humans.

Your task

Read about the idea of the Semantic web - you may use one of the resources below or look it up on your own.

Can you see how such a Semantic web could be used? Write your opinion on your blog.

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