Post-decision confidence, decision time, and self-reported decision processes as postdictors of identification accuracy

Abstract

Post-decision confidence, decision time, and decision processes were evaluated concerning their usefulness for postdicting identification accuracy. One hundred and ninety-two participants witnessed a filmed theft and were tested with target-absent or target-present simultaneous lineups 1 week later. Post-decision confidence was positively associated with, and decision time negatively associated with choosers’ identification accuracy. For several measures of self-reported decision processes, the expected associations were non-significant. Using a decision rule including highly confident and fast participants led to more correct classifications than either variable alone. Significant associations between postdictors highlight the need to consider the different processes jointly as, in combination, they may be more useful in assessing identification decisions.

Keywords:

• Post-decision confidence
• decision time
• automatic vs. eliminative decision processes
• recollective experience
• assessment variables

Acknowledgements

We wish to thank Franziska E. Holub, Sabine Bloss, Miriam Herder, Miriam Kirschner, and Nadine Lipke for their help in data collection.

Notes

1. In order to test for differences in modus of description, half of the participants followed a paper and pencil procedure resulting in a written description. The other half of the participants were videotaped while giving an oral description elicited in an interview. Identical instructions and questions were used for both groups. As there were no differences between these two conditions, this aspect of the experiment will not be discussed any further.

2. After the identification task, choosers were asked to make a Remember-Know(-Familiar) judgment (Tulving, 1985). However, the operationalization of the variable failed to elicit a satisfactory number of Know answers, thus not allowing any meaningful comparisons. Therefore, the results will not be discussed.

3. No separate analyses for target-absent lineups are possible as choosers are always incorrect in target-absent lineups.

4. No separate analyses for target-present and target-absent lineups were carried out, as nonchoosers are always correct in target-absent lineups, and always incorrect in target-present lineups.

5. As displayed in Table II, the last item loaded relatively high on both factors, although the loading on memory match strategy was non-significant.