The normal, equal variance model of signal detection theory, expressed with respect to log stimulus magnitude as metric, provides an account of discriminations between two separate stimulus magnitudes of an accuracy rarely encountered within experimental psychology. It models the signal detection operating characteristic, the psychometric function, and Weber's Law; this is demonstrated by reference to appropriate data. One might say that ‘the phenomena of sensory discrimination [between separate stimuli] are uniform with respect to the logarithm of stimulus magnitude’. But Fechner's Law depends on a further assertion — that the ‘logarithmic metric measures the sensation experienced by the subject’, that may not be true.
Keywords: normal model; operating characteristic; psychometric function; sensory discrimination; signal detection theory; Weber's Law
Chapter. 7059 words. Illustrated.
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