What these errors add up to is that Watson really cannot process natural language in a very sophisticated way — if it did, it would not suffer from the category errors that marked so many if its wrong responses. Nor does it have much ability to perform the inference required to integrate several discrete pieces of knowledge, as required for understanding puns, jokes, wordplay, and allusions. On clues involving these skills and lacking search-engine-friendly keywords, Watson stumbled. And when it stumbled, it often seemed not just ignorant, but completely thoughtless.
I expect you could create an unbeatable Jeopardy! champion by allowing a human player to look at Watson’s weighted list of possible responses, even without the weights being nearly as accurate as Watson has them. While Watson assigns percentage-based confidence levels, any moderately educated human will be immediately be able to discriminate potential responses into the three relatively discrete categories “makes no sense,” “yes, that sounds right,” and “don’t know, but maybe.” Watson hasn’t come close to touching this.
In short, Watson is not anywhere close to possessing true understanding of its knowledge — neither conscious understanding of the sort humans experience, nor unconscious, rule-based syntactic and semantic understanding sufficient to imitate the conscious variety. (Stephen Wolfram’s post accessibly explains his effort to achieve the latter.) Watson does not bring us any closer, in other words, to building a Mr. Data, even if such a thing is possible. Nor does it put us much closer to an Enterprise ship’s computer, as many have suggested.