The use of Vocabulary in the Measurement of Intellectual Deterioration—A Review

Abstract

The problem of determining whether or not a particular individual has deteriorated intellectually or with respect to other skills is one which has exercised the ingenuity of clinical psychologists for a long time. Clearly the most satisfactory method from the point of view of reliability and validity is by means of the test-retest method over a given period of time, using tests for which adequate statistical information is available. However, since a direct estimate of the individual's previous level of intelligence is usually not available and since the psychologist often cannot wait six months or longer to obtain a direct retest, some method had to be devised which would overcome this difficulty. Babcock (1930) hit on the method of using the Vocabulary test as an estimate of previous level of intellectual ability and contrasting it with performance on other tests supposedly sensitive to deterioration in order to measure the amount of decline which had taken place.Some aspects of the use of vocabulary in clinical psychological testing have been reviewed by a number of writers (Cronbach, 1942; Feifel, 1949; Hunt, 1936; Jastak, 1949; Lewinski, 1948; Raven and Walshaw, 1944; Shakow, 1946), and the immense interest shown in vocabulary as a test may be inferred from the 101-page bibliography of vocabulary studies published by Dale (1949). However, previous reviews suffer from two defects in that (a) they do not attempt to cover the ground thoroughly or systematically, being usually introductory to an experiment, or not specifically concerned with the subject matter of this paper; and (b) they naturally give no information about the important research which has taken place in this field within the last few years. The present review has been undertaken for these reasons, and because of the intrinsic importance of the problem.