A fallacy in the use of median scale values in employee check lists

Abstract

The median (or the mean) scale score frequently is used to evaluate individuals on industrial merit rating scales developed with Thurstone's equal-appearing intervals method. When this is done, it is possible that the "better" of a group of employees may obtain the lower scores. A solution to this fallacy is to replace median values by positive and negative values obtained by subtracting a constant from each of the item medians, thereby giving a merit rating score for each employee which is the algebraic sum of the values obtained. (PsycInfo Database Record (c) 2025 APA, all rights reserved)