PERSONALITY: UNIDIMENSIONAL APPROACHES
There are a large number of psychological tests which are supposed to measure "personality." It is unfortunate that we cannot think of more discrete and descriptive titles for some of these tests, because some are quite limited in scope and do not cover all that is usually implied in the general concept personality. Another unfortunate consequence of our inadequate nomenclature is that we talk, for example, of interest tests, of attitude tests, and of personality tests. This makes it look as if attitude and interest tests were not personality tests. About all we can do to clear up the confusion is to remember that we use the term personality test in two senses: in a general way to cover all tests discussed in this volume and in a more specific way to connote those tests not given any subclassification, such as interest or attitude test.
In this chapter and in Chap. 7, we propose to discuss several approaches to the construction of personality tests, using this term in its more restricted meaning. We shall divide these tests into two categories: one will include unidimensional approaches, and the other will include multidimensional approaches. Unidimensional approaches are those in which one trait is defined or in which only one test score is secured. The trait involved may be narrow in scope or fairly broad, but whatever its nature, it is considered as a unitary function. Multidimensional approaches are those leading to several scores from the same set of items. These several scores may purport to cover the whole of personality or only a small segment of it. In either event different dimensions are covered, and the methods involved in developing such tests frequently are different from those used in the unidimensional approaches.