The MBTI® differs from most other personality instruments in that the theory upon which it is based postulates dichotomies. These dichotomies are believed to reflect innate psychological or mental dispositions. The requirement that the instrument reflect these dichotomies has been a major factor in the design of items, use of numerical information to determine type preferences, general psychometric properties, and interpretation of results of the MBTI.

The MBTI instrument identifies four separate dichotomies: Extroversion versus Introversion, Sensing versus Intuition, Thinking versus Feeling, and Judging versus Perceiving. An individual is assumed to have a preference for one of each pair of opposites over the other. The four preferences direct the characteristic use of perception and judgment by an individual. The particular preferences that interact in a person affect not only what is attended to in any given situation but also how conclusions are drawn about what has been perceived.

The Myers-Briggs personality questionnaire is designed to indicate equally valuable preferences and does not have right and wrong answers. Your frame of reference when selecting preferences is how you function most naturally, smoothly, and effortlessly, when you are not going “against the grain.”