Eliciting human intelligence: A conceptualization and empirical testing of the Scharff technique

Abstract

This thesis is on how to elicit intelligence from human sources with the principal aim being to examine the efficacy of the tactics employed by the renowned WWII interrogator Hanns Scharff. A novel experimental set-up (as well as new dependent measures) was introduced to evaluate the efficacy of different human intelligence gathering techniques. Participants were given information about a planned terrorist attack, asked to take on the role of “sources”, and instructed to be semi-cooperative in a subsequent interview. In Study I (N = 60), interviews were conducted over the phone. The Scharff technique (conceptualized to include five tactics) was compared to the direct approach (a combination of open-ended and specific questions). The Scharff technique resulted in relatively more new information and led sources to underestimate how much new information they revealed. With the Direct Approach, sources overestimated how much new information they revealed. In Study II (N = 119), interacting parties met face-to-face and the sources were allowed to lie. Two versions of the Scharff technique were compared to the direct approach. The Scharff confirmation technique made use of claims that included the correct alternative while the Scharff disconfirmation/confirmation technique made use of a mix of correct and incorrect claims. The Scharff confirmation technique resulted in more new information than the Scharff disconfirmation/confirmation technique and the direct approach. Sources interviewed using the Scharff techniques had a more difficult time reading the interviewer’s information objectives and underestimated their contribution of new information. Sources interviewed using the direct approach overestimated how much new information they revealed. In Study III (N = 200) the interview techniques were used with four different types of sources varying in both their levels of cooperation and capability to provide information as follows: (a) less willing/less able, (b) less willing/more able, (c) more willing, less able, and (d) more willing/more able. The Scharff technique was compared to the direct approach. Overall, the Scharff technique resulted in relatively more new information, particularly when interviewing less cooperative sources. Furthermore, sources interviewed using the Scharff technique had a more difficult time reading the interviewer’s information objectives and consistently underestimated their contribution of new information. This thesis provides a psychological framework for and a conceptualization of the Scharff technique. Furthermore, the thesis introduces an experimental set-up mirroring a human intelligence interaction and offers a new set of dependent measures for mapping the efficacy of intelligence gathering techniques. In sum, this thesis provides support for the Scharff technique as an effective tool for eliciting information from human sources.