Confidence ratings in speech perception research: Evaluation of an efficient technique for discrimination testing

Discriminability of voice onset time was determined for four naive Ss in order to evaluate the relative efficiency of a testing procedure which utilized confidence ratings along with the conventional oddity task. Ss rated their judgments on oddity trials as “very very sure,” “somewhat sure,” or “just guessing.” Each S’s discrimination scores were given weights according to his ratings, yielding functions that were compared with those computed using unweighted percent correct scores. The confidence-rating technique produced readily interpretable results with about one-third as many judgments as are needed when the conventional procedure is used. Possible problems with the interpretation of the functions and the generalizability of the technique are discussed.