This is a review of an article ... But how important !
Semantic Web, the term I translate to my native language as "Web full of Meaning" has not realized its promises - this is clear to everybody who watches after the development. Why?
Before I go to the article and thoughts in it (By Nigel Shadbolt, Wendy Hall and .., last but not least - Tim Berners-Lee Himself !!!), let me shortly tell what this "Web full of Meaning" was supposed to be?
Tim Berners-Lee wrote once (1999):
"I have a dream for the Web [in which computers] become capable of analyzing all the data on the Web – the content, links, and transactions between people and computers. A ‘Semantic Web’, which should make this possible, has yet to emerge, but when it does, the day-to-day mechanisms of trade, bureaucracy and our daily lives will be handled by machines talking to machines. The ‘intelligent agents’ people have touted for ages will finally materialize."
In another short explanation, we can contrast the current web which contains documents with future Semantic Web, which will contain ASSERTIONS and data that can be understood by machines - not only by us - humans.....
Tim Berners-Lee launched the Semantic Web in 2001 in seminal article in Scientific American.
The promise of the expression of meaning, unambiguous knowledge representation was great. We would be on a path to realize that promise through the use of RDF, Ontologies and intelligent agents.
8 years later - and we know where we are. We have Google. Nothing more :-)
What is the reason?
In 2006, Nigel Shadbolt, Wendy Hall and Tim Berners-Lee made a review of Semantic Web Development, after 5 years of the first article.
Honestly - I'm not impressed at all. We still do not understand why we do not have it, and there are no simple clues - when and how to get there.
Authors made interesting survey of the progress over that 5 years, and some of the achievements are really impressive - GRDDL - allows to extract RDF data from XML (XHTML), various steps done within Web Ontologies, web scale tagging (folksonomies).
But the article still falls short to explain the fundamental failure of the promise.
I have no enough knowledge to judge - I only know a tiny part of Semantic Web, so I will not even try to answer "why" !
But I quite often think of two things:
1) In the world, where "everything is miscellaneous" - do we ever have a chance to build "Web full of Meaning" ? See soem comments about it here.
2) We should start from small things. From Microformats, from simple RDFA and use them for simple, yet practical things - for example - to annotate all addresses we put into our websites with semantic information - THIS IS THE ADDRESS !!! And so on.
If we start from big ("deep" as authors write) ontologies - we can not start the ball rolling .....
Finally - I'm not even sure if I'm right. Semantic Web failure is the big mystery to me ....