This week I was lucky to attend a conference on the theme of elicitation of information. Hanns Scharff has been highly praised for the success of his techniques, in particular because he never used physical means to obtain the required information. See: Hanns Scharff - Wikipedia and the "nun saying" is from: The Nazi Interrogator Who Revealed the Value of Kindness I cite a short summary: I had heard of this method before, although now a few years ago and there is a thread on the camp where he worked, which mentions him: The Interrogaters-Dulag Luft The expert is Simon Oleszkiewicz, a Swede who teaches at Vrije University Amsterdam; he is an experimental psychologist and is not a historian. His slim bio: Simon Oleszkiewicz and his articles are listed on: Simon Oleszkiewicz | Vrije Universiteit Amsterdam - Academia.edu There are a good number of articles on Scarff and this one by Simon and others (one a USAF interrogator), has an extensive bibliography: (PDF) The Scharff Technique: On How to Effectively Elicit Intelligence from Human Sources Note Scarff was deployed to a camp on the Western Front, primarily interrogating downed pilots and sometimes others. After WW2 Scarff emigrated to the USA, where he taught his technique before the Korean War and presumably afterwards. Several WW2 questions come to mind, kept for a later post.