The Arbitrary Nature of Holland's RIASEC Types: A Concentric-Circles Structure

Samples of high school (n = 370) and college (n = 223) students completed the Vocational Preference Inventory (J.L. Holland, 1985b) and the Inventory of Occupational Preference (IOP; T.J. Tracey & J. Rounds, in press). Their responses were examined with respect to whether they fit a uniform circular distribution. For both the high school and college samples, the individual interest items were uniformly arranged in a circle, indicating that there are no preferred points around the circle. Also, the 8 IOP octant scales and the 6 RIASEC scales (i.e., Realistic, Investigative, Artistic, Social, Enterprising, and Conventional) fit the data equally well, indicating that the 6 RIASEC scales are only one of many scale configurations that will fit a circular ordering. The results confirm that vocational interests have a uniform distribution along a circle and that the number of scales used is a matter of convenience. The relative utility of 6 or 8 scales and viewing interests as a set of concentric circles are discussed.