Myers–Briggs Type Indicator
The Myers–Briggs Type Indicator (MBTI) is a self-report questionnaire that makes pseudoscientific claims to categorize individuals into 16 distinct psychological types (often called personality types). The test assigns a binary letter value to each of four dichotomous categories: introversion or extraversion, sensing or intuition, thinking or feeling, and judging or perceiving.
Source: Wikipedia — Myers–Briggs Type Indicator (CC BY-SA 4.0)