Sometimes enough people misunderstand what you say that you begin to wonder how you could have said it more clearly. This is one of those times.
In the NYT piece on Watson I talked about Watson’s famous Toronto flub. In response to the clue “Its largest airport is named for a World War II hero; its second largest for a World War II battle,” given in the category “U.S. Cities,” Watson answered “Toronto.” It turns out, Toronto is not a U.S. City. (Well, at least the one that Watson picked out is not a U.S. City.) “This is the kind of blunder that practically no human being would make,” I wrote.
I can’t tell you how many putative refutations of this argument I’ve read that have begun with paeans to the stupidity of the average American. Jay Leno has proven, these comments usually begin, that most Americans don’t know diddly squat. Probably most of them don’t know that Toronto is not a U.S. City. Ergo, the fact that Watson didn’t know Toronto is in Canada doesn’t show that it’s not thinking at all.
The blunder people took me to be attributing to Watson, in other words, was the blunder of thinking that Toronto is a U.S. City. But that’s not what I was saying at all. Let me be perfectly clear. The explanation of the blunder offered by the IBM team does not go by way of suggesting that Watson had some good evidence for the claim that Toronto is a U.S. City. Watson, with its equivalent of one million books of information about the world, has plenty of evidence that Toronto is in Canada. (And evidence, too, that Canada is not part of the United States.) Its mistake was not to claim that Toronto is in the U.S., but rather to downplay the importance of that fact in choosing its answer. In particular, it downplayed the mismatch between the category (“U.S. Cities”) and the answer type (a non-U.S. city). This is the mistake I thought it would be hard for a person (who understands Jeopardy) to make. That is, the mistake of knowing that Toronto is not a U.S. City, knowing that the category is U.S. Cities, knowing that Chicago (its second guess) is a U.S. City, and nevertheless choosing Toronto. The idea is that even if it is sometimes inappropriate to worry about a mismatch between category and answer type, any human being familiar with the game would recognize that this is not one of those times. They would recognize, in other words, that the fact that there is sometimes a mismatch between category and answer type is simply not relevant in this situation.
People make howlers too, of course. But this is not the kind of howler people make. Instead, this is the kind of howler that betrays, as Ken Jennings said, that Watson is simply doing something different from us. That was the point. I hope it’s clearer now.