How did you get there?
When I saw the machine give its answer to the final Jeopardy question, I wasn't surprised at the wrongness of the answer, but I became curious as to how it came to that wrong answer.
The clue that the human host (Trebeck) gave was to name
(a) a city, with
(b) two airports, where
(c) one airport was named for a World War II general, and
(d) the second airport was named for a World War II battle.
Watson's answer of Toronto satisfied
(a) as it was the name of a city, but partly failed on
(b) as Toronto proper doesn't have two major airports, failed on
(c) as Toronto's main airport (Lester B. Pearson International Airport) is named after one of Canada's most popular Prime Ministers who never achieved the rank of general, and failed on
(d) because while there are tiny airports scattered around Metro Toronto, none of them are named for World War II battles.
When Watson proposed Toronto as its answer, had it checked each of these constraints in turn, it would have eliminated Toronto for its failure to satisfy three of the four constraints.
Now for Final Jeopardy, we didn't get to see the other answers that Watson was considering but didn't propose (for all the regular Jeopardy questions, we were shown on screen Watson's prime choice, and Watson's two alternate choices). So it's possible that Watson had Chicago in its list of possible answers, but for some reason, its internal ranking put Toronto higher than Chicago in its answer list.
I await tomorrow's (Wed, Feb 16th, 2011) last Jeopardy contest starring Watson with some interest. But I hold more interest for the possibility that the IBM team will answer some of these questions for us after the show.
Biting the hand that feeds IT
