Development of a q-set for MMPI-2 research with substance abusing populations in the USA

Research and clinical applications of q-methodology, in which a set of descriptive statements are sorted into a forced, quasi-normal distribution, have recently been extended to validation of integrated interpretations of the Minnesota Multiphasic Personality Inventory-2nd Edition (MMPI-2). This study aimed to develop a q-set customized for individuals diagnosed with substance abuse or those within a substance abuse treatment setting. 229 q-items, covering 11 content areas, were written to cover both the content area of the MMPI-2 and the variables affecting substance abuse treatment outcome. On the basis of their reliability, measured by inter-rater total correlation and variance components, 98 items were selected for final testing. Scores on this final q-set showed acceptable levels of reliability when forced into both a quasi-normal and flat distribution, with pairwise inter-rater reliability estimates of.519 and.517, respectively. Results of the study suggest the new q-set might be better suited to assessing a substance abusing population than the original Midwestern q-set that inspired it.