In signal detection theory, a plot of the proportion of false alarms (2) on the horizontal axis against the proportion of hits on the vertical axis (see illustration), the diagonal from bottom left (0, 0) to top right (1, 1) corresponding to a d prime of zero, and the curve obtained from a particular experiment always describing an arc above this diagonal, its precise form depending on the value of d prime, which in turn depends on the signal-to-noise ratio and the observer's sensitivity to the signal, different points on the curve representing variations in the observer's attitude towards the relative importance of misses and false alarms. See also memory operating characteristic. ROC abbrev.
Receiver operating characteristic. The observer at A is concerned to avoid misses and is willing to risk many false alarms, and at B is concerned to avoid false alarms and is willing to risk many misses; the observer at C is equally concerned about misses and false alarms.
Subjects: Chemistry — Psychology.