Turing test interrogators were restricted to one line of questioning per entity interaction. The restricted conversation rule was lifted for the 1995 Loebner Prize. Interaction duration between judge and entity has varied in Loebner Prizes. In Loebner 2003, at the University of Surrey, each interrogator was allowed five minutes to interact with an entity, machine or hidden-human. Between 2004 and 2007, the interaction time allowed in Loebner Prizes was more than twenty minutes. Saul Traiger argues that there are at least three primary versions of the Turing test, two of which are offered in "Computing Machinery and Intelligence" and one that he
Reverse Turing test much shared ground between the skill of the reverse Turing test and the skill of mentally simulating a program's operation in the course of computer programming and especially debugging. As a result, programmers (especially hackers) will sometimes indulge in an informal reverse Turing test for recreation. An informal reverse Turing test involves an attempt to simulate a computer without the formal structure of the Turing test. The judges of the test are typically not aware in advance that a reverse Turing test is occurring, and the test subject attempts to elicit from the 'judges' (who, correctly, think they are speaking