INTERQUARTILE RANGE By N., Sam M.S. - 2 Index of dispersion in a batch of scores. The difference between the 75th percentile and the 25th percentile scores in a distribution. INTERQUARTILE RANGE: "The interquartile range is an index of dispersion." Related Psychology Terms APRAXIA (literally, “inability to act or do”) RACE DIFFERENCES SCHOLASTIC APTITUDE TESTS WECHSLER MEMORY SCALE (WMS) JUST NOTICEABLE DIFFERENCE (JND; Differential or Difference Threshold) MUSIC TESTS STANDARD SCORE RORSCHACH TEST ADOLESCENCE (Theories) HEARING (AUDITION) Cite this page: N., Sam M.S., "INTERQUARTILE RANGE," in PsychologyDictionary.org, May 11, 2013, https://psychologydictionary.org/interquartile-range/ (accessed January 30, 2023).