Spatial Relations Tests
The discussion in Chapter II sought to point out that it was not necessary to think of group factors as entities or as mysterious faculties or as various kinds of intelligence, verbal, mathematical, spatial, and the like. We may picture systems of relationships obtaining between certain kinds of test items not holding as consistently among other kinds of items. One may explore for different systems of relationship as long as it is possible to devise new types of test items. The universe of things to be related is sufficiently broad to provide ample work for the future. Expeditions into this universe are not taken entirely at random but follow leads supplied by this investigation and that. Test investigations using spatial material probably go back to the interests of Galton and others in imagery types. This type of interest has also been fostered by the desire to measure the "intelligence" of people who have not been brought up in our own linguistic culture. Such tests usually bear the nondescript title of non-verbal tests and are sometimes said to measure "non-verbal intelligence." But we may ignore such great intellectual contributions forever, and turn to whatever techniques of investigation there may be at hand. One cannot defend any particular kind of test item at the outset except to say that to him it looks more promising than a test in Sanskrit, or heraldry, or the like. As data are accumulated concerning particular types of test items, the investigator may correlate his scores with outside criteria and then decide whether it is better to drop the whole collection of items or to make others.
The present writer has experimented with spatial relations tests for a number of years without moving either forward or backward. Tests 11, 14, 15, 17, and 18 reproduced in the preceding chapter illustrate the type of material used. In 1930 the writer decided to make another effort to study this type of test material and devised an entirely new collection of test items to which Mr. Warren G. Findley added another test (test 9 in the following collection). Tests 2, 4, and 8 in this collection were subsequently selected for further study and must be withheld now for that reason. Test 6 was quite similar to tests 2, 4, and 8, but as it seemed to be unnecessarily complicated it was deemed advisable to discontinue its use as a test, and to use the present results for more systematic exposition here. The following pages reproduce three items each of tests 2, 4, and 8, and all of the remaining tests tried out in 1930.
Our experience with verbal and numerical test items has led us to look for item situations which are: (1) valid, the validity being a result of the fact that