Numeric and verbal eyewitness confidence: order effects

The criminal justice system continues to obtain eyewitness confidence verbally (in the eyewitness’s own words). Because verbal confidence statements are challenging to interpret, eyewitnesses could provide scale ratings after verbal judgments or vice versa – if the confidence-accuracy relationship is maintained when both are obtained. Participants watched two videos and then viewed a target-present and target-absent lineups for the targets. After each lineup, participants provided confidence verbally (in their own words) and then numerically (0-100%) or numerically and then verbally. Asking eyewitnesses to provide confidence verbally and numerically did not negatively impact the confidence-accuracy relationship, regardless of order. However, the numeric values eyewitnesses provided when using similar own-word confidence judgments varied. We caution that the usefulness of verbal confidence to postdict identification accuracy hinges on a systematic approach to its interpretation.