Added Value of Subscores and Hypothesis Testing

The value-added method of Haberman is arguably one of the most popular methods to evaluate the quality of subscores. According to the method, a subscore has added value if the reliability of the subscore is larger than a quantity referred to as the proportional reduction in mean squared error of the total score. This article shows how well-known statistical tests can be used to determine the added value of subscores and augmented subscores. The usefulness of the suggested tests is demonstrated using two operational data sets