20Q

The principle is that the player thinks of something and the 20Q artificial intelligence asks a series of questions before guessing what the player is thinking. This artificial intelligence learns on its own with the information relayed back to the players who interact with it, and is not programmed. The player can answer these questions with: Yes, No, Unknown, and Sometimes. The experiment is based on the classic word game of Twenty Questions, and on the computer game "Animals," popular in the early 1970s, which used a somewhat simpler method to guess an animal.[3]

The 20Q AI uses an artificial neural network to pick the questions and to guess.[1][4] After the player has answered the twenty questions posed (sometimes fewer), 20Q makes a guess. If it is incorrect, it asks more questions, then guesses again. It makes guesses based on what it has learned; it is not programmed with information or what the inventor thinks. Answers to any question are based on players’ interpretations of the questions asked. Newer editions were made for different categories, such as music 20Q which has the player think of a song, and Harry Potter 20Q, which has the player think of something from the world of the Harry Potter series.

The 20Q AI can draw its own conclusions on how to interpret the information. It can be described as more of a folk taxonomy than a taxonomy. Its knowledge develops with every game played. In this regard, the online version of the 20Q AI can be inaccurate because it gathers its answers from what people think rather than from what people know. Limitations of taxonomy are often overcome by the AI itself because it can learn and adapt. For example, if the player was thinking of a "Horse" and answered "No" to the question "Is it an animal?," the AI will, nevertheless, guess correctly, despite being told that a horse is not an animal.

Patent applications in the US and Europe were submitted in 2005.[5][6]

In August 2014, 20Q.net Inc., with Brashworks Studios, developed and released an iOS iPad version available at the Apple iTunes store.

The built Artificial Neural Network is not resource intensive either to store or to compute, thus it could be embedded in small, less powerful devices. Currently, there is a handheld version of the AI. The device contains a small portion of the original 20Q website knowledge base; unlike the online versions of the game, the handheld version does not have the ability to learn.

The 20Q artificial intelligence is different from less flexible, and extremely large, expert systems. Its modularity, adaptability, and scalability means that it can be applied to other, more complex devices, for more complex uses.

On June 13, 2009, GSN began a TV version of the game, hosted by Cat Deeley, with Hal Sparks as the voice of Mr. Q.

• Twenty questions
• Akinator

• Official 20Q Website
• Open source Twenty Questions app, an open source implementation of 20Q with the code available on github