The Vocational Preference Inventory (VPI) is one of two inventories operationalizing John L. Holland’s person-environment fit theory. The other inventory, the Self-Directed Search, is intended to simulate the vocational guidance experience, whereas the VPI is intended to be a personality-interest inventory. The item content of the VPI consists of 160 occupational titles. Respondents choose either “like” or “dislike” to each of the occupations. A fundamental assumption that guided the construction of the VPI is that occupational preference is an expression of a person’s motivation, personality, knowledge, and ability. Furthermore, it is assumed that occupational preferences also indicate the favored methods of coping with interpersonal and environmental problems.
The purpose of the inventory is fourfold. First, it can be used as a brief assessment of personality with high school and college students as well as employed adults. Second, it can be a useful complement to other personality assessment instruments. Third, it provides a means of assessing vocational interests. Fourth, it can be used to assess the vocational behavior in the context of Holland’s theory.
The inventory can be used with people at least 14 years old and of normal intelligence. Generally, most people complete the inventory in 15 to 30 minutes, and hand scoring takes about a minute. The VPI has been used with diverse populations, including high school and college students, prison populations, employed adults, and psychiatric patients.
The VPI contains 11 scales that provide information regarding the test taker’s interests, self-conceptions, interpersonal relationships, and coping behaviors. Six of the scales represent Holland’s conceptualization of vocational personality types: Realistic, Investigative, Artistic, Social, Enterprising, and Conventional. These six scales make up what is commonly referred to as the RIASEC hexagonal dimensional model of personality and environments that is central to Holland’s theory. While the VPI is primarily used as a personality inventory, scores from the aforementioned scales can be used to derive a person’s vocational personality profile and hence used to identify potentially suitable occupations. This is accomplished by examining the three highest scores among the scales and matching them against occupational codes found in the Dictionary of Holland Occupational Codes or the Self-Directed Search Form R Occupations Finder.
The five other scales tap into other aspects of personality that career counselors would find helpful in interpreting results: Self-Control, Masculinity-Femininity, Status, Infrequency, and Acquiescence. On each scale it is assumed that high scorers have the traits associated with each scale and that low scorers possess the opposite of the traits associated with each scale. Brief conceptual definitions of each scale are offered below.
- Realistic scale: This scale represents traits associated with being pragmatic and conventional. Those with high scores tend to be described as being mechanically or technically inclined, interpersonally reserved, candid, and obstinate and are lacking social skills.
- Investigative scale: This scale represents traits associated with being rational and intellectual. High scorers tend to be scientifically inclined and are scholarly, curious, shy, and independent.
- Artistic scale: This scale represents traits associated with expressiveness and creativity. High scorers tend to be inclined toward artistic endeavors, and are sensitive, imaginative, emotional, open to new ideas, and unconventional.
- Social scale: This scale represents traits associated with friendliness and social responsibility. High scorers tend to be inclined to help others, and are extroverted, amiable, and dependent.
- Enterprising scale: This scale represents traits associated with social dominance and adventurousness. High scorers tend to be inclined to lead or persuade others, and are energetic, extroverted, and enthusiastic.
- Conventional scale: This scale represents traits associated with conformity and orderliness. High scorers tend to be inclined toward organizational or computational activities, and are practical, cautious, and traditional.
- Self-Control scale: This scale represents traits associated with impulse control and responsibility. High scorers are inclined to be inhibited, insecure, cautious, and passive.
- Masculinity-Femininity scale: This scale represents identification with stereotypical male and female roles. High scorers typically prefer traditionally male occupations, whereas low scorers prefer traditionally female occupations. High scorers are also typically characterized as being asocial, competitive, and shrewd.
- Status scale: This scale represents a person’s concern with prestige. High scorers generally prefer occupations that are high in social status and reflect a degree of self-confidence or desire for upward mobility.
- Infrequency scale: This scale represents a person’s preference for unpopular occupations. High scorers may have unsuccessful work histories and may view themselves in disparaging terms.
- Acquiescence scale: This scale represents a person’s degree of yea saying. High scorers tend to report liking many occupations. Extremely high scorers may represent lack of self-knowledge or someone with multiple interests and abilities.
The scales of the VPI generally have good internal consistency reliability estimates, with a few notable exceptions being the Masculinity-Femininity, Status, and Infrequency scales, which are quite low and should be interpreted with some caution. The scales that represent the RIASEC typology have demonstrated a moderate degree of predictive validity with high school and college students in terms of selection of an academic major and choice of occupation. The remaining scales show a moderate degree of convergence with similar scales on other personality inventories.
Users of the VPI should consider the person’s age, education, area of vocational training, and occupational status. For the purposes of vocational guidance, the RIASEC scales should be examined for their degree of differentiation and consistency. Differentiation refers to the magnitude of difference between the highest and lowest scores on the RIASEC scales. The greater the difference, the more clearly a person resembles one type and less like the others and hence should be more predictable in terms of appropriate vocational choice. Consistency refers to the degree of relatedness between personality types as represented in the hexagonal model. The closer the types on the hexagon, the greater the degree of overlap in terms of interests and traits. The other scales may provide additional information that can either reaffirm or elucidate score meaning of the RIASEC scales and may serve as additional information to help clarify a person’s self-concept and how it relates to choice of an occupation.
- Holland, J. L. 1958. “A Personality Inventory Employing Occupational Titles.” Journal of Applied Psychology 42:336-342.
- Holland, J. L. 1985. Vocational Preference Inventory (VPI) Manual. Odessa, FL: Psychological Assessment Resources.
- Holland, J. L. 1997. Making Vocational Choices. 3d ed. Odessa, FL: Psychological Assessment Resources.