A Test of a Short PEACE Interview Training Course: Training Efficacy and Individual Differences

Using a policing student sample ( N = 38) in a quasi-experimental research design, we examined whether a short training course on the PEACE model of investigative interviewing would impact mock interview performance and whether this impact would vary with individual differences. Interview performance was assessed via seven measures: (1) interviewee perception scale, (2) interviewer behavior scale, (3) interview length, (4) question appropriateness, (5) number of details elicited, (6) number of questions, and (7) detail per question. The efficacy of the training course was demonstrated through post-training performance increases in the interviewer behavior scores ( d = 0.79), detail per question ( d = 8.85), interview length ( d = 0.82), witness perception scores ( d = 0.45), and number of details ( d = 0.47). The Big Five personality scale and Police Interviewing Competencies Inventory (PICI) were used to measure individual differences. The Communicative-Insisting and Humane dimensions of the PICI and the Openness dimension of the Big Five scale predicted training efficacy. The potential implications of these findings for investigatory agencies are discussed.