The Conversion of Test Scores into Series Which Shall Have Any Assigned Mean and Degree of Dispersion

Abstract

It is frequently desired to convert the test scores from a group of subjects into a new series, which shall be directly comparable with some other standard series. Sometimes it is desired to convert the scores from a number of mental tests into strictly comparable series for the purpose of plotting mental profiles. The respective series of scores must have the same mean and the same degree of dispersion as measured by the mean variation or the standard variation. A method of making such conversion is presented. The formula is X = K + SX 1 . The mathematical derivation of the formula may be obtained by applying to the author. M = mean of converted series, S = ς/ς 1 , K = M - S M 1 , X = individual score of converted series. From Psych Bulletin 20:09:00986. (PsycINFO Database Record (c) 2016 APA, all rights reserved)