Assessing the Capacity to Build Rapport in Investigative Interviews with the Rapport-Based Inventory – Short Form (RBI-SF) Scale

Abstract

Introduction: Investigative interviewer training has increasingly focused on enhancing interviewers’ ability to build rapport with subjects; however, trainers currently lack a consistent and efficient method to assess individuals’ competence in using rapport-based skills. To address this, we have developed a self-report scale – the Rapport Based Inventory (RBI), which is a scenario-based assessment intended to measure interviewers’ recognition of the correct use of rapport-based skills in interviewing contexts. The original scale consisted of four vignettes with 16 items requiring free text and multiple-choice responses in which core rapport concepts are tested. The current study aims to examine the scale’s psychometric properties, underlying factor structure and construct validity.Methods: To test the instrument’s psychometric properties, the RBI was administered online to 225 participants (140 practitioners and 85 university students). To assess convergent (construct) validity, additional data was collected from a subsample of 60 practitioners taking part in interview training to examine whether RBI scores were associated with practitioners’ interview performance during mock interviews. Performance was coded using the rapport skills scales from the Observing Rapport Based Techniques (ORBIT) coding framework (Alison & Alison, 2012).Results: The final short form version of the RBI scale (RBI-SF) contains eight items across four investigative interviewing vignettes, comprised of two factors – reflective listening (six items) and developing discrepancies (two items) with good internal reliability. One item relating to adaptability was also retained as a separate item that should be administered alongside the RBI due to its theoretical and statistical significance. Correlational analyses revealed that the scale demonstrated convergent validity with behavioural measures of rapport-based skill, with RBI scores positively correlated with interviewers’ effective use of rapport-based behaviours and negatively correlated with rapport-inconsistent behaviours during mock interviews.Conclusions: We conclude that the newly developed instrument appears to be a promising tool to support the identification of interviewers’ accurate comprehension of rapport-building skills in the context of law enforcement and intelligence interviewing.