Open-domain quiz answering on Jeopardy!

The task was answering natural-language clues drawn from general knowledge, under quiz-show rules, against the two strongest players in the show's history. Watson received the clues as text, pressed a mechanical buzzer, and its errors were visible on air, including a Final Jeopardy answer of Toronto in a category about US cities. Speed on the buzzer mattered, and so did retrieval over a fixed corpus rather than reasoning. The result was not disputed, and open-domain question answering by machines has only widened the gap since.