What distinguishes the difference threshold from the absolute threshold?

The distinction between the difference threshold and the absolute threshold centers on their definitions and the contexts in which they are used. The absolute threshold refers to the minimum intensity of a stimulus required for it to be detected 50% of the time. In contrast, the difference threshold, also known as the just noticeable difference (JND), specifically refers to the smallest amount of change in a stimulus that can be detected.

This measurement is essential in understanding how individuals perceive differences in stimuli rather than just the presence or absence of a stimulus. For example, if you have a weight of 100 grams, the difference threshold would determine how much additional weight is needed for you to notice that the weight has increased. Thus, the difference threshold being the minimum difference required for detection captures the essence of what differentiates it from the absolute threshold.