The confidence-accuracy relationship using scale versus other methods of assessing confidence.

Abstract

Historically, researchers have collected eyewitness identification confidence using scales; however, in practice, eyewitnesses are more commonly asked for a verbal statement. In Experiment 1, participants viewed a simultaneous lineup and provided confidence in their own words, by explaining why they made their decision, or by selecting from statements made by real eyewitnesses, and then provided a scale rating (0-100%) or provided only the scale rating. In Experiment 2, participants viewed a sequential lineup and provided confidence in their own words followed by the scale rating or only the scale rating.Confidence predicted identification accuracy in all conditions, although verbal statements were highly variable and challenging to interpret. For example, only when scale-based confidence was high (80%+) did interpretation of the verbal confidence statement reliably align with scale-based confidence. These data highlight the complexity of verbal confidence statements and the need to establish meaningful boundaries for interpreting verbal confidence statements.

When did this happen? Indicators of accuracy for dating recent and remote personal events.

“…First, our approach to measuring confidence did not allow the examination of a fine-grained relationship between confidence and accuracy, which would require a much larger sample size. We intended to minimize demands on the interpretation of confidence rating instructions (and recent research suggests that participant interpretations of these instructions vary, e.g., Mansour, 2020), and we believe that our two-step approach (i.e., asking about confidence in the estimate and then asking whether participants would be willing to testify under oath) effectively separated highly confident participants, whose responses were accurate in 74%–85% of cases.…”