Combination of Types

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 RIASEC Holland Code is a theory of how people choose careers. It says, for example, that RI people (those whose strongest interests are in the Realistic and Investigative themes), will seek out RI jobs. "Engineer" is one of many occupations, which has an RI code. The R and I themes are close to each other on the hexagon and therefore share a common stronger interest of working with things rather than working with people. The themes are multidimensional; this is but one level.

College majors and over 12,000 occupations have been coded in this way and can provide useful and insightful information about where you might find satisfaction in the World of Work.