I'll try to answer this and Mike Tintner's question at the same time. The typical GOFAI engine over the past decades has had a layer structure something like this:
Problem-specific assertions Inference engine/database Lisp on top of the machine and OS. Now it turns out that this is plenty to build a system that can configure VAX computers or do NLP at the level of "Why did you put the red block on the blue one?" or "What is the capital of the largest country in North America?" The problem is that this leaves your "symbols" as atomic tokens in a logic-like environment, whose meaning is determined entirely from above, i.e. solely by virtue of their placement in expressions (or equivalently, links to other symbols in a "semantic network"). These formulations of a top layer were largely built on introspection, as was logic (and the Turing machine!). So chances are that a reasonable top layer could be built like that -- but the underpinnings are something a lot more capable than token-expression pattern matching. there's a big gap between the top layer(s) as found in AI programs and the bottom layers as found in existing programming systems. This is what I call "Formalist Float" in the book. It's not that any existing level is wrong, but there aren't enough of them, so that the higher ones aren't being built on the right primitives in current systems. Word-level concepts in the mind are much more elastic and plastic than logic tokens. You can build a factory where everything is made top-down, constructed with full attention to all its details. But if you try to build a farm that way, you'll do a huge amount of work and not get much -- your crops and livestock have to grow for themselves (and it's still a huge amount of work!). I think that the intermediate levels in the brain are built of robotic body controllers, mechanism with a flavor much like cybernetics, simply because that's what evolution had to work with. That's my working assumption in my experiments, anyway. Josh On Monday 11 June 2007 04:41:13 am Joshua Fox wrote: > Josh, > > Your point about layering makes perfect sense. > > I just ordered your book, but, impatient as I am, could I ask a question > about this, though I've asked a similar question before: Why have not the > elite of intelligent and open-minded leading AI researchers not attempted a > multi-layered approach? > > Joshua ----- This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?member_id=231415&user_secret=e9e40a7e
