It's kind of the "grandfather" of personality tests. Originally developed by two people who were "self-taught" in psychometric testing to be used helping women enter the workforce during WWII. In my studies, most personality tests don't really "test" your personality type. Personality is just a cluster of traits and behaviors that remain relatively stable throughout life, so any test should be taken as more of an introspective look into your self rather than a concrete, definitive "THIS IS ME" stance. I think the Big 5 (or OCEAN) test is actually much more reliable and easy to follow. Just my 2 cents.
