An Approach to the Measurement of Individual Differences in Personality*

Abstract

This Study outlines an approach to the measurement of individual differences in personality. The approach was suggested by a gross observational comparison of mental hospital patients and college students. This comparison was refined by means of an original method of scaling and scoring the answers given to psychological inventories. HISTORICAL REVIEWThe Investigation of Individual Differences Individual differences in various aspects of behavior were first noted by gross observational comparison of individuals. The observational comparisons were then refined by means of measurement techniques. The measurement techniques have involved the following assumptions:(a) that a linear continuum exists; (b) that tests or test-items can be allocated on the continuum, in graduated order, according to a defined principle; and (c) that the tests or test-items can be used to allocate individuals along the continuum.These assumptions are said to be justified, and the results obtained with the continuum are said to be psychologically significant, if:(a) the results differentiate between individuals in a manner similar to that of another criterion (e.g., the observational comparison) ; (b) two or more continua with different tests or test-items give similar results; (c) the tests or test-items show internal consistency; and if (d) the attribute or factor measured can be given psychological meaning.* Thesis, accepted as partial fulfillment of requirements for the Ph.D. degree, the University of Toronto.

Effective Items in the Measurement of Personality Integration—I

“…Some of the problems indicated herein are reported on more fully in subsequent papers. 2 Appreciation is expressed to the Research Board of the University of Illinois for financial aid in support of this study, and to Mr. Russell J. Jessen and Mrs. Gail Pheney Jessen, Research Assistants. II8 logical characteristics of items which are found to differ from one another empirically in their effectiveness in measuring personality integration.…”

“…Before outlining differences in results deriving from these three groups of item pairs, it is helpful to discuss various differences in our scoring methods. In our previous studies (2,4,7), and in the item analysis of the present study, we included two scoring steps which were omitted in all other portions of this study. They were omitted even though a previous study (2) had found that one of these steps increased the correlation between two tests of the variable under consideration, and also increased the difference between group means of patients and a group of normals.…”

“…In our previous studies (2,4,7), and in the item analysis of the present study, we included two scoring steps which were omitted in all other portions of this study. They were omitted even though a previous study (2) had found that one of these steps increased the correlation between two tests of the variable under consideration, and also increased the difference between group means of patients and a group of normals. They were left out of the present study because they complicate scoring, and because a secondary purpose of the present study is to discover items that are effective with a simpler scoring method.…”

“…In addition to the above 92 subjective items and 32 objective items, 63 items from previous studies of personality inventories were included (1, 2,3,9) because of two secondary purposes with which this study is concerned. One of these purposes is to obtain an indication of the breadth of the measure under consideration.…”

“…Instead, it evaluates patterns of responses according to their empirical similarity-diversity (2,4,5,7). Some pairs of responses are highly similar in the sense that if one response occurs the chance for the occurrence of the other response is high.…”