Wikipedia
Discan is both a scale and a method in clinical psychology. As a scale, it is a type of ordered-metric scaling that yields a scale with internal reliability, and scale-points in excess of the number of initial anchors, more than would be the case with the Likert scale, though not as many as are achieved by the Analog scale. In Louis Thurstone's tradition, it is scored by paired-comparisons. Seeking optimality, it is a compromise between the competing merits and demerits of the Likert scale and the Analog scale.
With the Discan method, four descriptive anchor-levels yield 14 scale-points, or three levels produce ten.
It was originated, for use in clinical psychology, by M.B. Shapiro.
For more detail, see Nomothetic and Idiographic.
A staging approach to measuring patient-centred subjective outcomes. Bilsbury CD, Richman A. Acta Psychiatr Scand Suppl. 2002;(414):5-40.
Category:Clinical psychology