Evaluating eyewitnesses: Translating expressions of pre- and post-identification confidence

Although the confidence-accuracy relationship is now well established, confidence assessments are usually taken after the lineup identification procedure. Witnesses, however, often express confidence in their potential identification accuracy at other times, such as prior to seeing a lineup. Recent research has shown that these post-identification confidence statements are not consistently interpreted in the manner witnesses intend them. The present studies compare interpretations of pre- and post-identification confidence statements, and examine whether these interpretations are similarly affected by numerical statements and featural justifications. Across four studies, participants read eyewitness confidence statements and judged how confident and accurate they perceived witnesses to be. We manipulated expression type (verbal, numerical), statement type (confidence only, confidence paired with justification), and statement time (pre- and post-identification). Pre-identification confidence statements were perceived as less confident and less likely to be accurate. Unlike post-identification statements, pre-identification statements were not discounted when accompanied by featural justifications.