The corroboration time measure: An implicit confidence judgement

The corroboration time technique is introduced as a means of eliciting covert confidence judgements. A validation experiment is reported in which three measures based upon the corroboration time are compared with overt confidence judgements. It is concluded that the technique yields a valid, sensitive measure of confidence which is as sensitive as an overt confidence judgement to variations in the independent variable, and which is less intrusive in use. It may be used whenever there is a unique correct response which can given as feedback for corroboration.