RELATIVITY OF JUDGMENTS ABOUT SOUND AMPLITUDE AND THE ASYMMETRY OF THE SAME DIFFERENT ROC

The problem of deciding whether two things are the same or different i n magnitude can be solved by judging one magnitude relative to the oth er, or by making absolute judgements about the magnitude of each. The shape of the resulting receiver operating characteristic depends on wh ich solution is adopted. In order to obtain empirical receiver operati ng characteristics, we therefore had subjects rate their confidence th at two tone amplitudes were the same or different. Four subjects each made 500 ratings of three differences in amplitude. The asymmetry in t he obtained characteristics indicated that subjects made relative rath er than absolute judgements of the amplitudes, despite the fact that m aking absolute judgements would lead to better performance on the task .