The Holland Codes or the Holland Occupational Code (HOC) represents a set of personality types described in a theory of careers and vocational choice formulated by the late psychologist John L. Holland.

Dr. Holland (1985) created Holland Code Career Model, Holland Hexagon Model or Holland Codes.

Each of the six types (Realistic, Investigative, Artistic, Social, Enterprising, Conventional) or RIASEC reflect Holland's theory that "the choice of a vocation is an expression of personality."

The Occupational Codes are:

  • Realistic
  • Investigative
  • Artistic
  • Social
  • Enterprising and
  • Conventional

The more a person is able to express their personality within a compatible work environment, the higher the likelihood of finding career satisfaction.