California Psychological Inventory (CPI)

California Psychological Inventory (CPI)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 may be used for more specific exploration after the vector scores have been interpreted.

The CPI has several strong features to recommend its usage. An extensive manual with over 400 pages, including appendices and references, is a significant resource. The standardized reports for results on individuals are well designed and organized. These reports include reliability data, graphical and narrative description of lifestyle type and level for the individual (based on the three vector scores), a graphical profile for the individual on the 20 folk scales with same-sex norms and mixed-sex norms, and helpful interpretive information for use by professionals. The standardized report also includes results for seven of the special-purpose scales that would often be relevant in the context of career assessment or exploration. The use of nonpathological constructs in common usage is a noteworthy advantage of the CPI in use with normal populations. The folk constructs were selected to maximize cross-cultural applications. Its emphasis on constructs with significant social relevance is also a useful characteristic in practice. The related applications guide serves as a resource for those working in career development areas.

Strengths and weaknesses of the CPI have been thoroughly addressed in the literature over the last four decades. Certain theoretical criticisms of the CPI have persisted over the years but do not distract from the applied uses of the instrument. Since the 1987 revision, one controversy over the CPI has involved the development of the vector scores and their use in forming the types and levels of the cuboid model of personality. Anne Anastasi and Susana Urbina discussed the implications of converting continuous-scale scores to dichotomous groupings and further pointed out issues related to measuring personality types or categories instead of continuously distributed constructs. In recent years, psychometricians have argued for and against such practices, depending on their theoretical views of the nature of personality and demands of its assessment. There seem to be reasonable arguments on both sides of this issue. Since the 1987 revision, the CPI has included serious efforts to define and validate the four types based on lifestyle or personality characteristics. Alternatively, the availability, validity, and usefulness of the folk scales of the CPI remain intact, so that one need not rely on the typologies provided. In fact, continued research on the relationship of the typologies to the folk scales seems important.

The relevance of the CPI to career development in general is highly notable. Gough provided a thorough review of several applications of the CPI to the world of career and work. Jody Newman, Elizabeth Gray, and Dale Fuqua reported substantial relationships between factors and scales of the CPI and career indecision status, while other researchers found relationships between career maturity and both personality type and social adjustment as measured by the CPI. Growing interest in the relationships among personality constructs and vocational interests may also support career-related uses of the CPI. There is little doubt that the CPI will continue to be a major resource for career development professionals and the clients they serve.

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References:

  1. Anastasi, A. and Urbina, S. 1997. Psychological Testing. 7th ed. Upper Saddle River, NJ: Prentice Hall. Gough, H. G. 1995. “Career Assessment and the California Psychological Inventory.” Journal of Career Assessment 3:101-122.
  2. Gough, H. G. and Bradley, P. 1996. CPI Manual. 3d ed. Palo Alto, CA: Consulting Psychologists Press.
  3. Newman, J. L., Gray, E. and Fuqua, D. R. 1999. “The Relation of Career Indecision to Personality Dimensions of the California Psychological Inventory.” Journal of Vocational Behavior 54:174-187.