Convergent Validity of Five Observational Rating Scales as Measures of Rapport in Investigative Interviews and Interrogations

Research suggests that rapport can play an integral role in the success of investigative interviews. Accurate measurement of rapport is therefore critical. However, published scales designed to measure rapport in investigative interviews require interviewee self-report or complex behavioral coding. Global observer ratings of rapport may be more practical for use in law enforcement and national security interview training. In the present study, novice observers rated 92 simulated investigative interviews on three dimensions of rapport using quick, global rating scales. All observer ratings scales were significantly related to interviewee self-report ratings of analogous dimensions of rapport. Further, scores on all observer scales were found to be higher when interviewers used rapport-based tactics. Two scales were significantly related to amount of information shared by sources during interviews. These results provide evidence for the validity of observational global ratings in investigative interviews. Global observer scales that are quick to complete and require little training can provide useful ratings of rapport in both research and practical applications