The enhanced cognitive interview: expressions of uncertainty, motivation and its relation with report accuracy

The Enhanced Cognitive Interview (ECI) is one of the most widely studied and used methods to interview witnesses. However, ECI research has mainly focused on increasing report size and somewhat overlooked how to improve and evaluate report accuracy. No study evaluated if witnesses’ spontaneous expressions of uncertainty are accurate metacognitive judgments, nor if witnesses’ motivation during the interview affects report accuracy. This study examined how witnesses’ judgments of recall ‘uncertainty’ and their motivation perception could relate to report accuracy. Forty-four psychology students watched a mock robbery video recording and were interviewed 48 hours later with either the Portuguese version of the ECI or a Structured Interview (SI). Afterward, participants’ motivation was assessed and items of information were classified as ‘certainties’ or ‘uncertainties’. Results suggest that our ECI protocol was effective, since participants interviewed with the ECI produced more information without compromising accuracy. ‘Uncertainties’ were less accurate than ‘certainties’, and their exclusion raised overall, ECI, and SI, accuracy. More motivated participants had better recall accuracy. Accounting for witnesses’ motivation and spontaneous verbal expressions of uncertainty may be effective and time-saving procedures to increase accuracy. These are key points that professionals and researchers should consider.