A successive approximation method of maximizing test validity

The ratio of item validity to item-total correlation can be used to select items which will tend to yield the maximum correlation with a criterion. Items to be retained are identified by comparing the ratio for each item with the validity of the original test. Further improvement of the validity in the experimental sample can be obtained by adding items to or removing items from the selected nucleus, according to recomputed ratios involving the correlations of the items with the nucleus and evaluated by means of a revised cut-off point. With slight variations, the method may be used for interest and personality tests as well as for aptitude material. The principal advantage over previous methods is that for any cycle of the analysis an exact cut-off point is provided.