California Psychological Inventory

The California Psychological Inventory (CPI) was first published in 1956. It has a historical relationship to the Minnesota Multiphasic Personality Inventory (MMPI) and shares many items with the older, well-known MMPI. The CPI has been studied extensively and has been widely used in both research and applied contexts. As a general-purpose personality assessment tool, it is widely respected and arguably the most effective instrument available for use with normal populations.

An important source of the utility of the CPI is found in its structural complexity. Use of the CPI involves application and interpretation of the instrument at three different levels. The CPI consists of 20 dimensions of personality with a strong interpersonal orientation. The most recent version of the CPI employs 434 items. Three of the 20 scales are validity scales that assess attitudes related to test taking. Harrison Gough has referred to the dimensions measured by the basic scales as “folk concepts,” that is, concepts that are used in routine daily life by people to describe patterns of behavior in themselves and others. Empirical methods of construction involving contrasted groups were used in developing 13 scales. Four scales were developed using internal consistency as the primary construction strategy, and 3 were constructed using a combination of empirical methods with the internal consistency criterion. In almost 50 years since its first publication, considerable validity evidence has collectively accumulated for these scales.

The structural characteristics of the 20 scales have been studied extensively. In general, five factors appear to underlie the 20 basic scales of the CPI. Although factor analysis was not a method employed in developing the CPI scales, a relatively stable factor structure has been reported that generally resembles the one reported in the CPI manual.

One of the guiding principles in the development of the CPI was that it was to be an open system, a system of constructs to which others might be added if they proved to be useful or necessary for some particular purpose. Indeed, a number of special-purpose scales have been developed, such as Managerial Potential, Work Orientation, and Leadership. The scoring keys for 13 scales designed for special purposes are provided in the CPI manual.

A major feature emerging from the 1987 revision of the CPI was the addition of three vector scales. The specific procedures by which these vector scales were actually developed have been a source of some criticism of the CPI. Nonetheless, these vectors are recommended as a source of information in profile interpretation. Vectors 1 (External vs. Internal) and 2 (Norm Favoring vs. Norm Questioning) are placed in perpendicular relationship to one another to create four types: Alphas, Betas, Gammas, and Deltas. The four types represent types of lifestyles into which individuals may be classified as the first level of profile interpretation. The third vector, Level of Realization, forms the third dimension of a cuboid model of personality structure and is represented on a seven-point scale. Individuals' ratings on this scale reflect the degree of ego integration and realization of the positive potential of their type. The 20 basic scales [Page 58]may be used for more specific exploration after the vector scores have been interpreted.

...