Glossary

Searchable terminology from accessibility, web standards, and related fields.

Just-Noticeable Difference (JND, Difference Threshold, Differential Threshold, Just Noticeable Difference)

The smallest detectable difference between two stimuli that a person can perceive. In accessibility contexts, JND is commonly applied to color, contrast, and audio levels—determining the minimum chang…

• perception
• color accessibility
• psychophysics

Magnitude Estimation (Psychophysical Scaling, Stevens Method)

A psychophysics research method where participants assign numerical values to stimuli based on their perceived intensity or magnitude. In accessibility research, magnitude estimation is used to determ…

• research methodology
• psychophysics