The Scharff-technique: eliciting intelligence from human sources

This study is on how to elicit intelligence from human sources. We compared the efficacy of two human intelligence gathering techniques: the Scharff-technique (conceptualized as four different tactics) and the Direct Approach (a combination of open and direct questions). Participants (N = 60) were asked to take on the role of "sources" and were given information about a planned terrorist attack. They were to reveal part of this information in an upcoming interview. Critically, the participants were instructed to strike a balance between not revealing too much or too little information. As predicted, the participants revealed significantly more, and more precise, new information when interviewed with the Scharff-technique (vs. the Direct Approach). Furthermore, and as predicted, the participants in the Scharff condition underestimated how much new information they revealed whereas the participants in the Direct Approach overestimated how much new information they revealed. The study provides rather strong support for the Scharff-technique as an effective human intelligence gathering technique.