One of the more prominent models in contemporary psychology is what is known as the five-factor model of personality. This theory incorporates five different variables into a conceptual model for describing personality. These five different factors are often referred to as the "Big 5". The five-factor theory is among the newest models developed for the description of personality, and this model shows promise to be among the most practical and applicable models available in the field of personality psychology. Thorough critical attention is given to the proposal that the five-factor model is in fact a great theory.
As it became evident to many psychologists that, mathematically, combinations of five factors were useful in describing personality, there was a need to clearly define what these factors were. Indeed, this process led to some dissent in the ranks. One dissenter from the five-factor theorists was renowned psychologist H. J. Eysenck. Eysenck felt that, due to overlaps in the five factors and their correlates, in fact a three-factor model was more appropriate and accurate. His theory is called the PEN model (which stand for psychoticism, extroversion, neuroticism), or sometimes is even shortened to the two factor E-IN model (extroversion-introversion, neuroticism).
Many psychologists support Eysenck 's PEN model. However, of the major "factor-analytic models...the Big Five dominates the landscape of current psychological research" (Ewen, 1998, p. 141). Through extensive debating and