In the early 1980s Douglas Lenat wrote EURISKO, a program Eliezer called "[maybe] the most sophisticated self-improving AI ever built". The program reportedly had some high-profile successes in various domains, like becoming world champion at a certain wargame or designing good integrated circuits.
Despite requests Lenat never released the source code. You can download an introductory paper: "Why AM and EURISKO appear to work" [PDF]. Honestly, reading it leaves a programmer still mystified about the internal workings of the AI: for example, what does the main loop look like? Researchers supposedly answered such questions in a more detailed publication, "EURISKO: A program that learns new heuristics and domain concepts." Artificial Intelligence (21): pp. 61-98. I couldn't find that paper available for download anywhere, and being in Russia I found it quite tricky to get a paper version. Maybe you Americans will have better luck with your local library? And to the best of my knowledge no one ever succeeded in (or even seriously tried) confirming Lenat's EURISKO results.
Today in 2009 this state of affairs looks laughable. A 30-year-old pivotal breakthrough in a large and important field... that never even got reproduced. What if it was a gigantic case of Clever Hans? How do you know? You're supposed to be a scientist, little one.
So my proposal to the LessWrong community: let's reimplement EURISKO!
We have some competent programmers here, don't we? We have open source tools and languages that weren't around in 1980. We can build an open source implementation available for all to play. In my book this counts as solid progress in the AI field.
Hell, I'd do it on my own if I had the goddamn paper.
Update: RichardKennaway has put Lenat's detailed papers up online, see the comments.
I've just been Googling to see what became of EURISKO. The results are baffling. Despite its success in its time, there has been essentially no followup, and it has hardly been cited in the last ten years. Ken Haase claims improvements on EURISKO, but Eliezer disagrees; at any rate, the paper is vague and I cannot find Haase's thesis online. But if EURISKO is a dead end, I haven't found anything arguing that either.
Perhaps in a future where Friendly AI was achieved, emissaries are being/will be sent back in time to prevent any premature discovery of the key insights necessary for strong AI.
The most sensible explanation has, I think been mentioned previously: that EURISKO was both overhyped and a dead end. Perhaps the techniques it used fell apart rapidly in less rigid domains than rule-based wargaming, and perhaps its successes were very heavily guided by Lenat. It's somewhat telling that Lenat, the only one who really knows how it worked, went off to do something completely different from EURISKO.
In this regard, one could consider something like EURISKO not as a successful AI, but as a successful cognitive assistant for someone working in a... (read more)