IBM developed the Watson artificial-intelligence system that won the 2011 Jeopardy! exhibition.
Watson competed against champions Ken Jennings and Brad Rutter in a televised two-game Jeopardy! match. The system won the competition, demonstrating its ability to interpret natural-language clues, retrieve evidence from large collections of text, and rank possible answers with confidence estimates.
IBM built Watson using a combination of technologies rather than one simple algorithm. Its capabilities included natural-language processing, information retrieval, machine learning, and probabilistic answer scoring. For Jeopardy!, it had to handle puns, indirect clues, wordplay, and category context.
Watson is sometimes described as a chatbot, but its original Jeopardy! system was a question-answering platform designed for a specific competition. IBM later adapted the Watson name for business and healthcare products, although those applications differed from the televised system.