[doubleunplussed]

It's been a longstanding question of mine how these things were programmed. How did they construct the database of answers and questions, and what the answer to each question would be for each possible answer?

[Luc]

People could play the game at http://20q.net/ , and if it didn't guess your word it asked you to enter it. So it was trained by the players.

It's a neural net, so very efficient on small devices.

[c22]

https://patents.google.com/patent/US20060230008?oq=Artificia...

[aabbcc1241]

Looks similar to the https://akinator.com

[ableal]

Page is working nicely, albeit with " © 1988-2007, 20Q.net Inc.," in the game pages, -2017 in the front page.

[b4je7d7wb]

Maybe it's some reinforcement learning.