Confidence in Forced-Choice Recognition: What Underlies the Ratings?

Two-alternative forced-choice recognition tests are commonly used to assess recognition accuracy that is uncontaminated by changes in bias. In such tests, participants are asked to endorse the studied item out of 2 presented alternatives. Participants may be further asked to provide confidence judgments for their recognition decisions. It is often assumed that both recognition decisions and confidence judgments in 2-alternative forced-choice recognition tests depend on participants' assessments of a difference in strength of memory evidence supporting the 2 alternatives-the relative account. In the present study we focus on the basis of confidence judgments and we assess the relative account of confidence against the absolute account of confidence, by which in assigning confidence participants consider only strength of memory evidence supporting the chosen alternative. The results of the study show that confidence in 2-alternative forced-choice recognition decisions is higher when memory evidence is stronger for the chosen alternative and also when memory evidence is stronger for the unchosen alternative. These patterns of results are consistent with the absolute account of confidence in 2-alternative forced-choice recognition but they are inconsistent with the relative account.