Simplified formula and table for the unusualness of combinations of subtest scores on the Shipley Institute of Living Scale.

This article addresses the issue of how one might judge the statistical uniqueness of a pair of subtest scores, taking into account the correlation between both scales. A simple formula to test the bivariate uniqueness of pairs of profile scores is presented and illustrated, using the Shipley Institute of Living Scale. The formula allows one to test the hypothesis that a particular combination of scores on the Shipley Vocabulary and Abstraction scales is unusual compared to the normative data.