A Note on Criterion Validity Loss in Scale Revision if Maximising Coefficient Alpha

This note is concerned with a validity-related limitation of the widely available and used index “alpha if item deleted” in the process of construction and development of multiplecomponent measuring instruments. Attention is drawn to the fact that this statistic can suggest dispensing with such scale components, whose removal leads to loss in criterion validity while maximising the popular coefficient alpha. As an alternative, a latent variable modelling approach is discussed that can be used for point and interval estimation of composite criterion validity (as well as reliability) after deletion of single components. The method can also be utilised to test conventional or minimum level hypotheses about associated population change in measurement quality indices.