Method of limits

The method of limits was one of three psychophysical methods for studying sensory absolute and differential thresholds developed by Gustav Fechner. See Method of constant stimuli and Method of adjustment for the other methods

The absolute threshold of a modality is examined by presenting a series of stimuli in ascending and descending steps and asking th subject to report if they detect it or not. The threshold is determined as the value that was detected 50% of the time.

A differential threshold is explored by presenting a series of stimuli in ascending and descending order and asking the observer to report on the size relative to a comparison stimulus. The threshold is determined to be the point at which the subject notes a just noticeable difference from the comparison stimulus on 50% of the trials

Papers

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