Cooke's disturbance index on the MMPI-2

Area of Science:

• Psychological assessment
• Personality testing
• Clinical psychology

Background:

• The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) is a widely used psychological assessment tool.
• Cooke's 1967 disturbance index is utilized in forensic psychology to assess potential malingering or response distortion.

Purpose of the Study:

• To investigate the impact of shortened MMPI-2 scales on Cooke's disturbance index.
• To propose and validate methods for adjusting MMPI-2 scale scores when using shortened versions for disturbance index calculation.

Main Methods:

• Analysis of MMPI-2 data using both full and shortened scale versions.
• Development of score adjustment algorithms for shortened scales.
• Comparison of disturbance index values calculated with original and adjusted scores.

Main Results:

• Shortened MMPI-2 scales significantly affect the magnitude of Cooke's disturbance index.
• The proposed adjustment methods effectively mitigate the impact of scale shortening.
• Adjusted scores yield disturbance index values more comparable to those derived from full scales.

Conclusions:

• Caution is advised when interpreting Cooke's disturbance index with shortened MMPI-2 scales.
• The presented score adjustment techniques offer a reliable approach for maintaining index accuracy.
• These methods enhance the validity of forensic assessments using abbreviated MMPI-2 forms.