Variable
The original Kscale was intended to assess the defensive approach to responding that minimized the open
expression of psychopathology. This approach to answering items resulted in essentially normal profiles in indi-
viduals who clearly did possess identifiable pathology by other criteria.
Description
The original scale had 30 items that were selected empirically by the contrasted groups method used for the
early MMPI. The revised K-rscale (Adjustment Validity) has 14 items, two of which are true-keyed and 12 of
which are false-keyed. Previous versions of the MMPI have incorporated a correction procedure using the Kscale
for other scales. This correction is no longer used on the MMPI-2-RF.
Sample
The same sources as reported for the L-rscale apply to the K-rscale. The figures for the non-gendered norm
sample give a mean of 7.45 ( SD52.91) ( Tellegen & Ben-Porath, 2008 ).
Reliability
Internal Consistency
The MMPI-2-RF Technical Manual reports Cronbach alpha coefficients ranging from .67 to .76 in five samples
ranging from the norm sample to two samples of psychiatric inpatients.
Test/C0Retest
Tellegen and Ben-Porath (2008) reported a test /C0retest reliability coefficient of .84 over a one-week interval
(N5193).
Validity
Convergent/Concurrent
The Technical Manual ( Tellegen & Ben-Porath, 2008 ) reports correlations among the various MMPI-2-RF valid-
ity indices. Sellbom and Bagby (2008) reported that the K-rscale functions as a measure of defensiveness in
responding in groups instructed to fake good as compared to those given standard instructions.
Criterion/Predictive
Sellbom and Bagby (2008) also reported that a group of individuals undergoing child custody evaluations
exhibited higher scores on the K-rscale in comparison with undergraduate students responding under standard
instructions.
Location
Ben-Porath, Y. S., & Tellegen, A. (2008). MMPI-2-RF: Minnesota Multiphasic Personality Inventory-2 Restructured
Form. Manual for administration, scoring, and administration . Minneapolis: University of Minnesota Press.
Tellegen, A., & Ben-Porath, Y. S. (2008). MMPI-2-RF: Minnesota Multiphasic Personality Inventory-2 Restructured
Form. Technical manual . Minneapolis: University of Minnesota Press.
Results and Comments
The K-rscale represents a substantial change to the older Kscale, having fewer than half the items. This has
likely led to an increase in its utility as well. It likely is also an advance in practice that the K-correction is no lon-
ger applied to clinical scales in the RFform. The limited research to date is encouraging in that it appears to find
more evidence for the validity of the K-rscale.
MEASURES OF OVER-REPORTING
MMPI F Scales
(Tellegen & Ben-Porath, 2008 ).30 2. RESPONSE BIAS, MALINGERING, AND IMPRESSION MANAGEMENT
I. INTRODUCTION: CORE ISSUES IN ASSESSMENT