The Myers-Briggs Type Indicator® (MBTI) instrument is a psychological instrument which provides information about Jungian based personality or psychological types. It is not considered to be a test or evaluative instrument, and there are no right or wrong answers on the MBTI instrument. The responses to the questions give an indication of the person's psychological type, and all types are positive or good.
The MBTI instrument is similar to other psychological instruments in that it is a paper-and-pencil instrument designed to assess some qualities of one's personality. People are asked to respond to questions about their preferences in various situations, and the result is an indicated "type" of personality. Knowing one's type gives insight into one's motives, behaviors and interactions with others.
The MBTI instrument is unlike many other psychological instruments in that it is not an assessment of mental health, intelligence, or unhealthy personality types or patterns. The common psychological instrument may tell you, among other things, where you are deficient, lacking or disturbed. It is not possible to have an MBTI result that is bad or unhealthy. The MBTI instrument is intended for self-discovery — what is right with you.
It does not measure amounts of personality traits or quantities of thought or behavior. Most psychological instruments report high or low amounts of a good or bad trait. The MBTI instrument sorts personalities into different types that are qualitatively different. Just as apples are different than oranges, one personality type is different from other types. Trait theory would tell you how much orange and how much apple you are (everyone is fruit salad).
It does not compare your results to that of other individuals. Most psychological tests evaluate you by comparing you to some normal or pathological standard. With the MBTI instrument your responses are the only values used to indicate your psychological type. Whether or not you are an Extravert or an Introvert is the important issue, not how you compare to other Extraverts or Introverts.
It does not tell you what you are. Usually the results of a psychological instrument are the final word. You are depressed or dysfunctional in some way and the test told you so. With the MBTI instrument, the type that the person reports on the Indicator is a hypothesis that needs to be verified by the respondent as he or she considers the descriptions of the reported and different types. This leads to a best-fit type, and continued self-assessment may result in an accurate indication of type that is different than the reported results.