Reasons for the revision of MMPI
1) The original MMPI was the most frequently used personality test in the U.S. It was even strongly endorsed by groups such as the Society for Personality Assessment (which primarily uses projective techniques) and the American Association for Behavioral Therapy.
2) The MMPI had not been revised since its publication in 1943.
3) The original standardization sample was not adequate (not generalizable)
4) There was concern regarding the item content of the original MMPI (language was archaic, some of the language was sexist, items dealt with Christian religious beliefs, etc)
5) The original MMPI had not undergone editorial review ( there were grammatical errors, double negatives, etc)
6) The original MMPI was too narrow in scope. Issues relating to suicide attempts, drug and alcohol abuse, were not addressed