ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06
2pPP39. The effects of criterion variability on relative operating
characteristics.
William S. Brown
Brookhaven Natl. Lab., Bldg. 130, Upton, NY 11973-5000
David S. Emmerich
State Univ. of New York at Stony Brook, Stony Brook, NY 11974
The form of the relative operating characteristic (ROC) describing
auditory detection typically differs from that expected based on the assumption
that the observer's responses reflect underlying distributions that are normal
and of equal variance [e.g., Green and Swets, Signal Detection Theory and
Psychophysics]. Specifically, it is found that binormal ROCs often have slopes
less than one, and are not strictly linear [Watson et al., 283--288
(1964)]. It has been suggested that nonlinear binormal ROCs may be the result
of extreme criteria being more variable than those more centrally positioned
[Emmerich and Binder, J. Acoust. Soc. Am. Suppl. 1 65, S59 (1979)]. The forms
of rating ROCs obtained in an experiment designed to reveal the effects of such
variability were consistent with the proposition that criteria associated with
``no'' responses are more variable than those associated with ``yes''
responses. Criterion operating characteristics [Wickelgren, J. Math. Psychol.
5, 102--122], which reflect the relative locations and variances of the
boundaries of confidence categories, favored the same interpretation. It is
concluded that the variability of criteria defining categories of rated
confidence is sizable and not necessarily constant across criteria, and that
such variability significantly influences the forms of empirical ROCs
determined using confidence ratings in auditory signal detection.