PSYCO367 Chapter Notes -Detection Theory, Receiver Operating Characteristic

• School: University of Alberta
• Department: Psychology
• Course: PSYCO367
• Professor: Douglas Wylie

Document Summary

Psychophysical procedure such as the method of constant stimuli: at least 5 different stimulus intensities are presented and stimulus is presented on every trial. Signal detection only uses low intensity tones that are difficult to hear. Present a tone on some trials and not on others. Thus a signal detection experiment different from a classical psychophysical experiment in two ways: only one stimulus intensity is presented, on some of the trials, no stimulus is presented. Hit: saying yes when a stimulus is present. Miss: saying no when a stimulus is present. Alarm: saying yes when there is no stimulus. Correct rejection: saying no when there is no stimulus. Payoffs: motivation, way to change the percentage of hits and false alarms. Receiver operating characteristics: the curve of responses of a person under differing payoffs. Roc curve shows that factors other than sensitivity to the stimulus determine a persons response. If two peoples roc curve are identical, they have the same sensitivity.