People in the research and development area, had developed a psychological measurement tool, which measures the personality type of a person.
Personality type refers to the psychological classification of different types of individuals. Personality types are sometimes distinguished from personality traits, with the latter embodying a smaller grouping of behavioral tendencies. Types are sometimes said to involve qualitative differences between people, whereas traits might be construed as quantitative differences. According to type theories, for example, introverts and extraverts are two fundamentally different categories of people.
Then some other theorists developed another tool which measures the same stuff, but in a different way. In this tool, people have been classified into six different types: investigative, artistic, social, enterprising, conventional and realistic.