Lecture 25: Language Games
CS442: Great Insights in Computer Science Michael L. Littman, Spring 2006
Long-standing Debate
What can computers do, in principle compute think learn make judgments exhibit creativity feel Are these things even separable
Chess is One Thing…
The drosophila of AI. Intellectual game, taxes the human mind. Simple in a sense: Choices, decision of winning/losing, all known in advance. Can live in the world of pure logic. No external inuences. Closed World Assumption
Real Life is Another
Navigating cross campus: No single right answer. Trade off energy, time, safety, etc. Affects other aspects of life. Changes over time! Learning, judgment, necessary. Open World Reality
Language Games
Like other games: Evaluation process clean. Challenging (and fun!) for people. Unlike logical games: No closed world assumption. "AI-complete"! Machine performance far from humans'.
Example
Down
44 Telephone call
44
R H I E N L G L S O
Is this move legal Is it wise
6
Word Games
Super-human performance common: Scrabble: Maven, near-perfect (Sheppard 02) Boggle: millisecond solutions (Boyan 98) Hangman (Littman 00) 99.97% 9-letter words under 5 guesses 1.35 misses on average
Trivial Pursuit
Race around board, answer questions. Categories: Geography, Entertainment, History, Literature, Science, Sports
Wigwam
QA via AQUA (Abney et al. 00) back off: word match in order helps score. "When was Amelia Earhart's last ight " 1937, 1897 (birth), 1997 (reenactment) Named entities only, 100G of web pages Move selection via MDP (Littman 00) Estimate category accuracy. Minimize expected turns to nish.
Wigwam's Knowledge
wigwam arts & literature entertainment science & nature geography history sports & leisure ~turns/game me buff web
.3 .3 .2 .1 .1 .025
414
.6 .3 .7 .2 .2 .6
48
.6 .5 .7 .4 .5 .7
22

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