E. H. Weber
worked on the problem of how we judge whether a stimulus, such as loud music, has increased or decreased in intensity (Ex. Frog in a boiling pot/Al Gore-Global warming)
concept of just noticeable difference (JND)
refers to the smallest increase or decrease in the intensity of a stimulus that a person is able to detect
Weber’s law
The increase in intensity of a stimulus needed to produce a just noticeable difference grows in proportion to the intensity of the initial stimulus.