Tuesday, February 15, 2011

Elementary, My Dear Watson?

As many of you know, this week IBM's computer system, Watson, is competing on Jeopardy against its two strongest performers, Ken Jennings and Brad Rutter. At the time of this post, their first match has finished, and Watson is ahead by a large margin.  Watson's lead is so great that it would be quite surprising if Ken or Brad were to catch up.  Given I do machine learning research (though I'd more call the Jeopardy task AI than ML), I couldn't resist posting about this match.

Ever since witnessing humanity's line fall when Deep Blue defeated Kasparov over a decade ago, we humans have become accustomed to computers outperforming us at various tasks.  Computers were first built precisely to do computations quicker and more accurately than we could hope to.  And even though winning at chess takes a lot more than brute-force computing power (if a computer really tried to calculate all possible chess move sequences, it would take more than the current age of the universe for it to finish), chess seems like one of those activities that computers should be good at.  Actually, the best humans can still easily defeat the best computer systems at Go, but few of us will be surprised when, in a couple years, this ceases to be the case.

Jeopardy is another thing all-together.  One might at first ask what possible hope is there of beating a computer at trivia.  Watson can download pretty much the entire internet into its memory (and has), but the problem is what to do with all this information.  And equally difficult is understanding the Jeopardy questions (or "answers" as they call them) in the first place.  Yesterday, Watson had a lot of trouble with the "name the decade" category precisely because it didn't know the answer had to be a decade.  Or in naming the murderer of Snape and others, Watson couldn't properly rank Voldemort over Harry Potter because, even though it had the entire book in its memory, it had no idea of the concept of murder -- only of word associations, and Harry and murder appear rather frequently together (you-know-who's fault).**

So the difficult part for Watson is exactly the easy part for humans (and vice versa).  Watson can easily store the name of every general, country, and battle, but has a lot more difficulty trying to figure out what is being asked.  Sure there are keywords like "he" or "this date," but when there's any ambiguity, it's quite a challenge.  And even if Watson figures out the answer is a date, it still does massive lookups, searches for correlations, runs machine learning algorithms, etc.  At any point, something can go wrong because Watson doesn't "understand" the way we do.  (Interestingly enough, as Louis von Ahn observes on twitter, the final Jeopardy question about city airport names was pretty hard to answer even for us humans using a search engine, though it wasn't so hard for Ken or Brad, but no human would answer Toronto for "U.S. cities").  Ken and Brad need no help interpreting the questions, but to them, remembering the ridiculous amount of information is the hard part.

That being said, the IBM team has done a great job with Watson.  Watson's performance this far already heralds other incredibly useful applications, which are not so unlike the Star Trek TNG computer systems -- only they'll come much before the 24th century.  Don't get me wrong; there's still quite a bit to go.  Real-life speech doesn't come in the form of nicely-formatted Jeopardy riddles (typed to Watson, who still doesn't have speech recognition), but this demonstration shows we've passed a major hurdle.

Finally, I should say that even though I believe that these technological changes are ultimately for the better, I am rooting for Ken and Brad*.  Once Watson can beat us, there's no going back.  In 10 more years, your typical personal computer, in whatever phone/laptop/terminal/watch shape it is, will run circles around Watson.

Yet, whatever discomfort I have will probably soon go away, and I'll become accustomed to computers being better than we are at yet another thing.  I'll take comfort in my personal better-than-Watson computer.  I'll enjoy the efficiency this brings.  I'll celebrate of the new scientific and medical breakthroughs we'll make using the help of (and closer interaction with) ever more powerful computers.  I'll, for one, eventually welcome our trivia overlords.

Update (2/16/11): Watson won today, as expected. And Daniel Reeves has some interesting ideas on how to change the rules of the game.

*I also felt that the game was a bit rigged against Ken and Brad -- the computer can always buzz in faster, so Ken and Brad have to compete for who wins the more human questions.  Were the game 1 on 1, it would have been a lot closer.  And if it were two Watsons vs just Ken or Brad, I'm sure the humans would win.

**Showing, once more that humans are decidedly more human, as we can easily tell the difference between Harry and Voldemort.

The image is of IBM's Watson Avatar and taken from Wikipedia.  It is posted for commentary under "fair use."