WWWhat does it all mean?

By: Shane Dempsey

Can you provide me with a list of pharmacies within a 10 mile radius that stock a specified quantity of a specified medicine?
Wouldn't it be very handy if you could ask your PC to do this for you?

Well, with the implementation of the Semantic Web this could be possible. One of the first things that a new arrival to the World Wide Web (also known as The Internet) is faced with is the sheer intimidating volume of data available. Formally, information is data that has been processed by some mechanism to make it useful to the reader. In general, people surf the web by searching for pages that match certain phrases using powerful search engines such as Google and Altavista. These searches return pages which contain the specified phrases.

Clearly for some popular words and phrases, e.g. 'computers', the search engine is going to return a lot of links. When presented with such huge volumes of data the average web surfer can often feel intimidated. Even battle-hardened information warriors will often find it difficult to find the precise piece of information that they're looking for! However, people are good at heuristic or rule of thumb-based reasoning. We can metaphorically see through the web by refining our searches and scanning the information we are presented with to determine which are the more valid links or web pages based on factors such as:

* The kind of information we expected to retrieve;
* The presentation of the information that we expected to retrieve;
* Experimentation and its resulting experience.

This sounds complicated and usually is. Sometimes our reasoning and memory fails us or the background data is insufficient to find the correct information. Even if we are successful, long web searches are hardly efficient. Arguably the web is still in its infancy and needs some new mechanisms to prevent it from becoming unusable. Many experts, including Tim Berners Lee who is regarded by some as the inventor of the World Wide Web, feel that the web needs more semantic information about web sites and their constituent data. This concept is being labelled the Semantic Web.

Creating the Semantic Web involves putting machine-understandable data on the Web so the huge volume of web data can be shared and processed by automated tools as well as by people. "For the Web to scale, tomorrow's programs must be able to share and process data even when these programs have been designed totally independently." [1]

The Semantic web vision involves using description languages such as Resource Description Framework (RDF) [2] and the cunningly titled Web Ontology Language (OWL) [3] to provide descriptions of the content and services available via the web. Soon, intelligent query engines may process these descriptions to provide answers to questions like the one at the beginning of this article.

This technology is clearly revolutionary, significantly impacting how effectively people can harness the information that surrounds them. The World Wide Web Consortium (W3C) is responsible for creating the impetus behind and standards for Semantic Web development efforts. Here in the TSSG we are currently evaluating the use of semantic web techniques to enable E-Learning and Smart-Space concepts. In Smart Spaces the electronic devices (e.g. mobile phone, PC etc.) that we use everyday display intelligence in the retrieval and presentation of information and services to end users. This is often known as Ubiquitous Computing. More about this in later columns.

[1] Semantic Web, W3C, 2001. www.w3.org/2001/sw/
[2] RDF - Concepts and Abstract Syntax, W3C, 2003, www.w3.org/TR/rdf-concepts/
[3] Web Ontology Language (OWL) Reference 1.0 www.w3.org/TR/owl-ref/