Some interesting Watson details
The top human Jeopardy players are very, very good, with the all-time champion answering nearly two-thirds of the questions in a match with 85 to 95 per cent accuracy. In 2007, the best the IBM team could manage was around 30 per cent accuracy, so they decided to shift their approach from sifting through large amounts of structured databases to looking at more unstructured data via Hadoop.
The second big shift in strategy was the abandonment of software rules wherever possible. Brown explained, for example, that while it might seem logical to set up a rule that a data set for “month” should only include the standard twelve, January to December, this left Watson flummoxed over questions of holy months such as Ramadan. Rather than set strict rules, the team relied on a statistical analysis of evidence to weigh probabilities of a specific answer being correct.