The Semantic Web, Syllogism, and Worldview
clay shirky says the semantic web won't work b/c it needs true statements in order to be effective.
In the real world, we are usually operating with partial, inconclusive or context-sensitive information. When we have to make a decision based on this information, we guess, extrapolate, intuit, we do what we did last time, we do what we think our friends would do or what Jesus or Joan Jett would have done, we do all of those things and more, but we almost never use actual deductive logic.
Syllogisms sound stilted in part because they traffic in absurd absolutes. Consider this gem from Dodgson:
- No interesting poems are unpopular among people of real taste
- No modern poetry is free from affectation
- All your poems are on the subject of soap-bubbles
- No affected poetry is popular among people of real taste
- No ancient poetry is on the subject of soap-bubbles
This, of course, allows you to conclude that all your poems are bad.
This 5-line syllogism is the best critique of the Semantic Web ever published, as its illustrates the kind of world we would have to live in for this form of reasoning to work, a world where language is merely math done with words. Actual human expression must take into account the ambiguities of the real world, where people, even those with real taste, disagree about what is interesting or affected, and where no poets, even the most uninteresting, write all their poems about soap bubbles.
(dodgson is charles dodgson or better known as lewis carroll)
for the semantic web to happen proponents of it say content needs to be marked up so it can be connected to other content and to users.
If the sole goal of the Semantic Web were pervasive markup, it would be nothing more than a "Got meta-data?" campaign -- a generic exhortation for developers to do what they are doing anyway. The second, and larger goal, however, is to take up the old Artificial Intelligence project in a new context.
After 50 years of work, the performance of machines designed to think about the world the way humans do has remained, to put it politely, sub-optimal. The Semantic Web sets out to address this by reversing the problem. Since it's hard to make machines think about the world, the new goal is to describe the world in ways that are easy for machines to think about.
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.
in response to enforcing smeantics on human relationships as seen in sites like friendster.com:
Trying to express implicit and fuzzy relationships in ways that are explicit and sharp doesn't clarify the meaning, it destroys it.
In an echo of Richard Gabriel's Worse is Better argumment, the Semantic Web imagines that completeness and correctness of data exposed on the web are the cardinal virtues, and that any amount of implementation complexity is acceptable in pursuit of those virtues. The problem is that the more semantic consistency required by a standard, the sharper the tradeoff between complexity and scale. It's easy to get broad agreement in a narrow group of users, or vice-versa, but not both.
The systems that have succeeded at scale have made simple implementation the core virtue, up the stack from Ethernet over Token Ring to the web over gopher and WAIS. The most widely adopted digital descriptor in history, the URL, regards semantics as a side conversation between consenting adults, and makes no requirements in this regard whatsoever: sports.yahoo.com/nfl/ is a valid URL, but so is 22.214.171.124/ftrjjk.ppq. The fact that a URL itself doesn't have to mean anything is essential -- the Web succeeded in part because it does not try to make any assertions about the meaning of the documents it contained, only about their location.