Tuesday, June 23, 2009

Introduction to the Holland Codes

Holland Codes represent a set of personality types described in a theory of careers and vocational choice formulated by psychologist John L. Holland. Holland's theory argued that "the choice of a vocation is an expression of personality" and that the six factor typology he articulated could be used to describe both persons and work environments.

His typology provides an interpretative structure for a number of different vocational interest surveys, including the two measures he developed: The Vocational Preference Inventory and the Self Directed Search. His model has been adopted by the U.S. Department of Labor for categorizing jobs relative to interests.

Holland's theory does not assume that a person is just one type or that there are "only six types of people in the world." Instead, he assumed that any person could be described as having interests associated with each of the six types in a descending order of preference. This assumption allows the Holland Codes to be used to describe 720 different personality patterns.

As the theory is applied in interest inventories and job classifications, it is usually only the two or three most dominant codes that are used for vocational guidance. In presenting his theory, Holland graphically represented the six types as arrayed on a hexagon. This graphic representation serves to describe the empirically determined correlations between the types. The shorter the distance between their corners on the hexagon, the more closely they are related.

Taken together, the Holland Codes are usually referred to by their first letters: RIASEC.

The six personality and work environment types described by Holland are as follows:
Realistic - practical, physical, hands-on, tool-oriented
Investigative - analytical, intellectual, scientific, explorative
Artistic - creative, original, independent, chaotic
Social - cooperative, supporting, helping, healing/nurturing
Enterprising - competitive environments, leadership, persuading
Conventional - detail-oriented, organizing, clerical