Minnesota Multiphasic Personality Inventory

Purpose: Designed as an objective personality test for the assessment of psychopathology.

Population: Adults.

Score: Reports scores for the various scales.

Time: (40-90) minutes.

Authors: Starke Hathaway and J. Charnley McKinley.

Publisher: University of Minnesota Press.

Description: The Minnesota Multiphasic Personality Inventory (MMPI) is an objective verbal inventory designed as an personality test for the assessment of psychopathology consisting of 550 statements, 16 of which are repeated. The replicated statements were originally included to facilitate the first attempt at scanner scoring. Though they are no longer needed for this purpose, they persist in the inventory.

Scoring: The inventory is scored in subunits, eight of which are conventionally termed clinical scales and provide the clinical profile. The clinical scales are Scale 1 (Hypochondriasis); Scale 2 (Depression); Scale 3 (Hysteria); Scale 4 (Psychopathic Deviate); Scale 6 (Paranoia); Scale 7 (Psychasthenia); Scale 8 (Schizophrenia); and Scale 9 (Hypomania). Two other scales were added from within the original item pool. Scale 5 (Masculinity-femininity) was developed along with the eight clinical scales. Shortly after, Scale 0 (Social Introversion) was added. Three additional measures were designed to estimate the validity of the clinical profile. The L (Lie) Scale has 25 statements each dealing with a common, relatively insignificant weakness to which most people are willing to confess. The F (Infrequency) Scale is made up of 64 statements that were answered in the keyed direction by less than 10% of the inventory’s original standardization group. The K Scale was designed to trap the respondent who attempts to conceal actual psychopathology.

Reliability: Test-retest reliabilities reported in the manual range from the .50s to the low .90s. Certain scales, such as Scale 2, are quite variable over time, whereas other scales supposedly more "characterological," such as Scale 1, have much higher test-retest reliabilities.

Validity: The validity of the MMPI varies with the population examined and the questions to be answered. The inventory has been the subject of thousands of studies and seemingly works best with diagnosing those who are severely disturbed and are demographically most like the original Minnesota normative sample (i.e., white and middle-class). The inventory seemingly is less valid with groups divergent from this population, such as those from different races or cultures.

Norms: The criterion groups were selected from patients at the University of Minnesota hospitals.

Suggested Uses: Uses include screening, assessment, selection, and prediction applications in both research and clinical settings.