| Abstract: | Clarification is given of the "paradox" posed by Loevinger (see 29: 3299), i.e., "validity" (the product-moment r of test score with the common factor of test items) decreases upon the increase beyond a certain point of item intercorrelations in a test whose items are of equal difficulty. Four points are made: (1) the "region of paradox" is reduced using a curvilinear r rather than the usual product-moment "validity"; (2) the paradox's incidence in aptitude and achievement tests is not as great as is frequently believed; (3) over-all "validity" for a group is inferior to the test's discriminating power for a specified decision problem for a specific examinee; and (4) the conception that "… for optimum results the percentage of correct answers to each item should equal the percentage of examinees to be selected" is correct only if the latter percentage is 50. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
