Validity Scales of the MMPI-2
The L Scale: Also referred to as the "lie scale," this validity scale was developed to detect attempts by patients to present themselves in a favorable light. People who score high on this scale deliberately try to present themselves in the most positive way possible, rejecting shortcomings or unfavorable characteristics. Well-educated people from higher social classes tend to score lower on the L scale.
The F Scale: This scale is used to detect attempts at "faking good" or "faking bad." Essentially, people who score high on this test are trying to appear better or worse than they really are. This scale asks questions designed to determine if test-takers are contradicting themselves in their responses.
The K Scale: Sometimes referred to as the “defensiveness scale,” this scale is a more effective and less obvious way of detecting attempts to present oneself in the best possible way. Research has demonstrated, however, that those of a higher educational level and socioeconomic status tend to score higher on the K Scale.
The ? Scale: Also known as the “cannot say” scale, this validity scale is the number of items left unanswered. The MMPI manual recommends that any test with 30 or more unanswered questions be declared invalid.
TRIN Scale: The True Response Inconsistency Scale was developed to detect patients who respond inconsistently. This section consists of 23 paired questions that are opposite of each other.
VRIN Scale: The Variable Response Inconsistency Scale is another method developed to detect inconsistent responses.
The Fb Scale: This scale is composed of 40 items that less than 10% of normal respondents support. High scores on this scale sometimes indicate that the respondent stopped paying attention and began answering questions randomly.