Isn’t there more to the Semantic web than Syllogism?


Syllogism. There are some words that I can’t get my head around. This one I did, finally. I have read about Aristotle and logic no end of times. Knowledge that happily flowed through me. I was caught up short as I perused Clay Shirky’s deep vault of delights. Articles that he had written several years ago.

Now I have been wide eyed at the Semantic web for a while now. I was wide eyed when I found out about email back in 1981, and distraught to see people agape at Fax machines. I toyed with the Internet, read about it in books anonymous ftp was amazing, and gopher? Blimey! People were aghast as I shrieked when I finally saw a web connection back in 1994 in the library at Heriot-Watt. An anecdote propping up no end of braying middle aged dinner parties.

So Semantic Web. The next big thing?

Medieval monks went to great lengths to illustrate their books, wonderous capitals spilling out in riotous ornate colours. Web pages too look quite amazing, but to a glum server choking on bits from around the world it knows nothing of natty pictures. But in a way the semantic web (via RDFa) illustrates the text of a web page.

More than words. It takes a lot of nous to get the meaning of a text. Data though can be larded in on the web, behind the scenes in the html unbeknownst to the reader can lurk labels and tags explaining what something is, or where. The reader can’t see it but search engines can, and so use it to deliver better results to advertisees.

OK. So only a tiny proportion of the Semantic web is embedded in web pages, virtually all of it resides in things called RDF triple stores. Triple because each piece of knowledge consists of three parts a subject, with a predicate giving rise to an object. “The sky  has the colour  blue” for example. Put enough of these statements together and you get a graph. Each part of these triple items is unique, it has its own URI to represent it. This is fine for  small area of knowledge but to meld these fields together one needs some way of translating them, and this is where OWL comes in, it allows one to work out how different vocabularies can fit together. So now you can search for similar patterns in large databases of Semantic data, using SPARQL (almost for the glory of Rome).

Now Clay Shirky’s article “The Semantic Web, Syllogism, and Worldview” predates embedded web knowledge. It is interesting to read his words, a lot has unfolded since then. The upshot is an extension of a criticism of AI, a branch of science devoted in making machines that can think. Logic is brittle, so the labels can quickly end up contradicting themselves making the whole thing pointless. As though the whole point is to deduce a deeper understanding of the world and not the rather more prosaic bait for agents scouring the web for the betterment of searches.

True now I think about it distilling an item into labels has its issues, and with that in mind you can’t construe too much. But there is plenty to be getting on with for the time being. Locations of restaurants, etc. One of the biggest users of the semantic web has been the biosciences, huge amount of data that needs to be cross referenced. The semantic web can feed their giant graph databases looking to turn up leads for new medicines. Now combing through data profitably looking for similarities, this isn’t AI to me but turning the cogs and wheels and crunching data. For AI to replicate a human I can only think of an imaginative machine. Perhaps this too is a mirage.

But murky knowledge muddies the pool. One piece of supporting evidence isn’t as much use as twenty more. This is how Cyc works, looking for a bit of evidence, but wary that what but me true might only be true locally, or just plain wrong. And now it has started to read, learning unaided by puny humans. The singularity started a year ago…


~ by zeristor on May 5, 2010.

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