This concept is based on the percent difference in perception known as Weber's constant, which is featured in Weber's law.  
This concept is based on the percent difference in perception known as Weber's constant, which is featured in Weber's law.  This law's fundamental characteristics are the absolute threshold, the difference limen, and the scaling of intensity to psychological intensity.  Providing a definition for the just-noticeable difference in stimuli, this law states that S equals k times the logarithm of R, or that sensation increases as the logarithm of stimulus intensity.  FTP, identify this law from psychology that provides a system of measuring a stimulus.
This concept is based on the percent difference in perception known as Weber's constant, which is featured in Weber's law.  
Fechner's law