A scale of measurement in which differences between values can be quantified in absolute terms but the zero point is fixed arbitrarily, familiar examples being Fahrenheit or Celsius temperature scales and calendar dates. In an interval scale, equal differences between scale scores correspond to equal differences in the attribute being measured, but there is no score corresponding to the total absence of the attribute. See also measurement level, method of equal-appearing intervals, scale, unfolding technique. Compare absolute scale, log-interval scale, nominal scale, ordinal scale, ratio scale. [From Latin intervallum space between, from inter between and vallum a rampart]
Subjects: Psychology — Probability and Statistics.