The F -K Index (Dissimulation Index)
The difference between scores on F and K has been used to provide an index of the likelihood that a person is producing an invalid profile. This index can be determined by subtracting the raw score (not T scores) on K from the raw score on F However, most research has indicated that it is not as effective as using the F scale to detect fake bad profiles (R. Baer et a l., 1999; Bagby et a l.. 1994, 1995). In addition, not enough is known about the MMPI-2 and MMPI-A F-K index to use it in detecting fake good pro- files. As a result, it is not recommended that this index be used.