November 11th, 2003


Why the Semantic Net won't work


Which reminds me of much of a conversation that myself and green_amber had recently, where our main point of agreement was that semantic games do not an AI make.

The Semantic Web specifies ways of exposing these kinds of assertions on the Web, so that third parties can combine them to discover things that are true but not specified directly. This is the promise of the Semantic Web -- it will improve all the areas of your life where you currently use syllogisms.

Which is to say, almost nowhere.

Descriptions of the Semantic Web exhibit an inversion of trivial and hard issues because the core goal does as well. The Semantic Web takes for granted that many important aspects of the world can be specified in an unambiguous and universally agreed-on fashion, then spends a great deal of time talking about the ideal XML formats for those descriptions. This puts the stress on the wrong part of the problem -- if the world were easy to describe, you could do it in Sanskrit.

Likewise, statements in the Semantic Web work as inputs to syllogistic logic not because syllogisms are a good way to deal with slippery, partial, or context-dependent statements -- they are not, for the reasons discussed above -- but rather because syllogisms are things computers do well. If the world can't be reduced to unambiguous statements that can be effortlessly recombined, then it will be hard to rescue the Artificial Intelligence project. And that, of course, would be unthinkable.

Any attempt at a global ontology is doomed to fail, because meta-data describes a worldview. The designers of the Soviet library's cataloging system were making an assertion about the world when they made the first category of books "Works of the classical authors of Marxism-Leninism." Charles Dewey was making an assertion about the world when he lumped all books about non-Christian religions into a single category, listed last among books about religion. It is not possible to neatly map these two systems onto one another, or onto other classification schemes -- they describe different kinds of worlds.

Because meta-data describes a worldview, incompatibility is an inevitable by-product of vigorous argument. It would be relatively easy, for example, to encode a description of genes in XML, but it would be impossible to get a universal standard for such a description, because biologists are still arguing about what a gene actually is. There are several competing standards for describing genetic information, and the semantic divergence is an artifact of a real conversation among biologists. You can't get a standard til you have an agreement, and you can't force an agreement to exist where none actually does.

Trying to express implicit and fuzzy relationships in ways that are explicit and sharp doesn't clarify the meaning, it destroys it.

Video Night

Finding myself over-extended and generally with too much to do for the next few weeks, it's off, until further notice.

If other people are watching videos, give me a shout :->


Just spent 3 hours with freemoore. covering various things to do with computers. He's studying computing as an MSc, so we went over some Object Oriented stuff, some pointer stuff, some database stuff, memory usage and a whole grab bag of little bits and pieces.

Absolutely great fun, and I get to do it again next week!