By Deane Barker on May 11, 2005

20Q: This is a cool little toy I played with over at a friend’s house. It’s shaped like a tennis ball with a little LCD screen and two buttons. You think of something (anything), and it asks you 20 questions to which you answer “yes” or “no.” Most of the time, it then correctly guesses what you were thinking of.

It has a chip in with logic based on this site, which has been “training” for years when people come to play with it.

Last year, after 1 million rounds of 20 questions online, the neural net had accumulated 10 million synaptic associations. It has a 73% success rate of guessing what you thought. Burgener then compressed the 20Q code to run on a chip, and had the neural net select 2,000 of the most popular 10,000 objects it then knew about. He then had the neural net select out the most useful 250,000 synaptic connections related to those 2,000 objects, and hard wired that learning into the chip in the orb.



  1. I saw a post on BoingBoing about this last night and tried the web-based 20Q a couple of times, and the thing was way off on its guesses. I wasn’t trying to trick it, but it made me wonder what its accuracy percentage is.

    When it’s wrong at the end of the questions it asks what you were thinking of; it must put your answer into its database for future users.

  2. I stumped it twice but it did guess my first object, a calculator. It was stumped on “a clock” and “a cd stomper”.

    these will make great christmas presents.

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