A Cycle-Omnibus Intelligence Test for College Students
L. L. Thurstone · The Journal of Educational Research · 1921
Intelligence tests were until recently used primarily to deter mine the mental age of children by the comparison of the chron ological age with the mental age. When mental tests are given to adults, this type of analysis is no longer suitable since the intelligence of adults does not increase noticeably with age. The intelligence tests are used with adults in order to place a given person's intelligence with reference to the distribution of general adult intelligence. The scores are, therefore, more suit ably expressed in terms of ranks or percentile ranks or of the standard deviation of the distribution of adult intelligence. An intelligence test should be so adapted as to its difficulty that it will differentiate into significant and distinguishable groups the population for which it is intended. This cannot well be done if the test is either too difficult or too easy. In general, however, a fairly symmetrical distribution of test scores will be obtained for any given population with tests of considerable variation in difficulty. The test for which I am here submitting some norms was arranged in difficulty as nearly as possible to suit college freshmen. During the last five years I have been experimenting with over fifty different varieties of mental tests with college freshmen at Carnegie Institute of Technology in its various departments. My procedure was the general one of giving the tests as early as possible in the freshman year, filing the scores until scholarship records and instructors' estimates could be obtained, and then determining the predictive value of each test by the correlations between its scores and the objective criteria of the students' abilities. I have found that instructors' estimates, on account of their unreliability, are, in general, unsuitable as a criterion by which to judge the predictive value of a mental test. The several instructors' estimates for the same student vary considerably more than the corresponding scholarship grades. Lately I have used scholarship records almost exclusively as the general criterion to determine the predictive value of a mental test. The procedure is quite different, however, in work 265