Myers-Briggs Type Indicator (MBTI) is a introspect self-report questionnaire about personality. The test assign people four binary indicators: Introversion or Extraversion, Sensing or iNtuition, Thinking or Feeling, and Judging or Perceiving. With that people are put into 16 distinct categories while each is labeled with letters such as “INTJ.”
MBTI is widely considered pseudoscience because of poor validity and reliability, measurement not being independent, and not being comprehensive. The positive perception of MBTI are said to be result of the Barnum effect.