The Role of Weighting in the Use of Aggregate Scores

Abstract

In a recent article, Gardner and Erdle (1984) have argued inappropriately against prior standardization of scores when an aggregate score is formed. They demonstrate that an aggregate of raw scores may not correlate perfectly with an aggregate of standard scores, and that the correlation of an external criterion with the two types of aggregates may differ markedly. However, these effects are not a function of standardization. They are an artifact resulting from the differential weighting of components in the process of aggregation. In fact, standardization improves the ability to interpret and compare scores. A demonstration of the effects of differential weighting of aggregate components is presented that clarifies the need for prior standardization. The conceptual role of standardization in statistics and the use of aggregate scores in research are also briefly discussed.