SENSORY THRESHOLDS AND SIGNAL DETECTION: ch 4

Weber’s law

a just noticeable difference often depends on the proportion of change relative to the starting stimulus, not only the absolute amount

Signal detection

hit, miss, false alarm, or correct rejection

hit

a signal exists and the observer reports it

miss

a signal exists but the observer does not report it

false alarm

no signal exists, but the observer reports one

correct rejection

no signal exists and the observer correctly reports none

liberal response criterion

more likely to say a signal is present; generally increases hits and false alarms

conservative resopnse criterion

less likely to say a signal is present; generally reduces false alarms but increases misses