Regulating accuracy on university tests with the plurality option

A single experiment is reported in which introductory psychology students were administered a multiple-choice test on psychology with either 4 (n = 78) or 5 alternatives (n = 92) prior to any lectures being delivered. Two answers were generated for each question: a small answer consisting of their favorite alternative, and a large answer consisting of all alternatives except for their least favorite one. They also rated confidence of the accuracy of both answers and selected one for grading (plurality option). Replicating previous research, there was evidence of a confidence-accuracy (C-A) dissociation for selected answers. Specifically, accuracy was higher, but confidence was lower, for selected large answers compared to selected small answers. However, unlike previous research, the C-A dissociation was coupled with marked underconfidence for both types of selected answers. The results are discussed in terms of option fixation, the base-rate fallacy, response criteria, and alternative plausibility.

► Students can regulate accuracy on multiple-choice tests by selecting more than one alternative.
► Students fail to increase their confidence ratings sufficiently when offering plural answers as opposed to single answers.
► Accuracy was higher, but confidence was lower, for selected large answers compared to selected small answers.
► The research extends previous research on the plurality option to an educational setting.