The Myers-Briggs Type Indicator ® (MBTI®) instrument is a self-report questionnaire designed to make Jung’s theory of psychological types understandable and useful in every-day life. MBTI® results identify valuable difference between normal, healthy people, difference that can be the source of much misunderstanding and miscommunication.
Type is more than just the sum of the four preferences. The four-letter MBTI® type formula is a shorthand way of telling you about the interaction of your four mental functions and which ones you prefer to use first. This is called type dynamics, and it is an important part of understanding your MBTI® results.