Thurstone Scaling

Thurstone Scaling, formally the Law of Comparative Judgment, is a psychometric model introduced by Louis Leon Thurstone in 1927 for deriving interval-level scale values from pairwise comparison data. By assuming that each stimulus evokes a normally distributed discriminal process on a psychological continuum, the method converts proportions of preference judgments into z-scores and recovers the latent positions of stimuli, enabling rigorous attitude and preference measurement.