How the scale-development process is conducted is critical, because the resulting scales will form the basis of the model of leadership, management, or effective performance that you will be presenting to the manager. Your task as the evaluator is to discover whether the process of scale construction seems reasonable and complete. To determine that, you will need to look in the technical manual or in published technical reports.

      There are typically two aspects of scale development: the statistical and the rational/intuitive. The statistical aspect involves using procedures such as factor analysis, cluster analysis, or item-scale correlations to group items into scales based on the degree of similarity in response patterns of the raters (for instance, people rated high on one item are also rated high on other items in that scale). The rational/intuitive aspect involves grouping items together based on the author’s expectations or experience about how different skills or behaviors relate to one another. Some instruments have used one of the two processes in developing scales from items and some have used both.