Monday, October 15, 2007

The Semantic Web and the Knowledge Reuse

Most of the Web's content today is designed for humans to read, not for computer programs to manipulate meaningfully. The Semantic Web will bring structure to the meaningful content of Web pages, creating an environment where software agents roaming from page to page can readily carry out sophisticated tasks for users. The Semantic Web is not a separate Web but an extension of the current one, in which information is given well-defined meaning, better enabling computers and people to work in cooperation. As benefits computers will find the meaning of semantic data by following hyperlinks to definitions of key terms and rules for reasoning about them logically. Search programs will be able to look for only those pages that refer to a precise concept instead of all the ones using ambiguous keywords. On the other hand, the Semantic Web infrastructure depends on additional investments over the current web and logically nobody wants to pay for that. The challenge of the Semantic Web Semantic Web, therefore, is to provide plug-ins to add the semantic features for current web development will low or none costs if possible.

As seem the meaningful of the content is the key point of the Semantic Web applications; this happens because Semantic Web Markup Languages such as OWL and RDF associate the content to be exhibited with its source: the domain ontologies. In computer science, ontologies correspond to documents that formally define the relations among entities of real-world. Moreover, ontologies play an important role in knowledge sharing and reuse since new the Semantic Web Markup formats can be easily published on the Internet. Today many different domain ontologies have been populating the web and making the knowledge reusable by anybody else. In a positive perspective, we believe this scenario tends to increase with the advent of Semantic Web applications. Example of this we can be seen at "Ontology library systems: The key to successful ontology reuse"[Y. Ding and D. Fensel., 2001].


Eduardo Almeida said...

Fred, I have some questions about your post. You said that users do not want to pay to “reorganize” their applications to obtain the advantages of semantic web. Yes, I think that it is very expensive, for example, to rebuild part of the available content. So the point is, ok; our next applications we will build this way. However, with Web 2.0, we have the applications being developed very fast to gain the market and this concern (incorporates the semantic web idea) is not being followed. What do you think about it? For example, the most famous sites such as youtube, flickr, orkut, etc are some examples. In our context, software reuse, often, we have this problem. Companies have a lot of data not structured and perform it is not trivial besides cost effective. In this scenario, what is your feeling to introduce it in reuse tools.

Jairson Vitorino said...

I happened to attend the 4th Congress in Web Semantics held in Darmstadt last week. I wrote a short summary of what has happened there here:
(in Portuguese)

I hope this makes it up for me not having done any comments on the Model Driven Engineering post.

Fred Durao said...

Good position Eduardo! Indeed you are completely right, the Web 2.0 is coming but their applications do not care about the Semantic Web. In my point of view, the latest web tools are more focused on their visibility in the trade market instead of investments in innovative features provided by Semantic Web. In fact, it is understandable because the owners (or creators) of such tools do not see the Semantic Web environment available on the Internet. There is no infrastructure where agents could surf to perform sophisticated tasks, for example (as Lee has envisioned). In this context, they hardly will give the first step towards the Semantic Web activity.

On the other hand, TODAY, applications that make use of Semantic Web resources turned to specific tasks have more probability of being successful. For example: Today many organizations have amounts of unstructured information spread in documents, so instead of make them totally well-structured (big cost $$$$), why not combine Information Retrieval Techniques with Ontologies to provide the knowledge reuse about this legacy content? The last option seems to be more reasonable and efficient. Therefore, I see that introducing reuse tools with semantic assistance as opportunistic investments considering the actual scenario of the organizations.

In Jairson’s blog, he confirms my prognostic about the Semantic Web: more and more application use Semantic Web resources for their own instead of sponsoring its development. We see proposal and assumptions, some time some isolated movement but invisible for the rest of the World. The question is: who will pay the Semantic Web bill?