THE CONSTRUCTION OF INTERNALLY CONSISTENT CONTENT SUBSCALES FOR THE MINNESOTA MULTIPHASIC PERSONALITY INVENTORY
Abstract
This research proposed to construct a set of internally consistent, nonoverlapping content subscales within the conventional scales of the Minnesota Multiphasic Personality Inventory (MMPI), in order to enhance its utility. Traditional use of the MMPI, one of the most commonly employed tools in psychological assessment, ignores a vast pool of potentially useful information: specific item content. In order to make that information accessible, reorganization of items into content oriented subsets was required. Both rational item analytic procedures were applied to 12 of the conventional MMPI scales (the L scale was excluded). Identification of categories of content and the initial composition of the subscales was accomplished via two sortings of items by independent groups of judges. From an original set of 45 content subscales, 27 final subscales were derived through statistical revision aimed at maximizing internal consistency as measured by Cronbach's coefficient alpha. Initially, subjects were 588 clinical inpatients and outpatients sampled to parallel national demographic statistics on users of mental health services. These subscales were considered to have respectable levels of internal consistency, and were mutually exclusive within conventional scales. These results were cross-validated on a second, random sample comparable to that employed in subscale derivation and again on a larger clinical sample of 2,537 cases. Tentative support for the concurrent validity of the content subscales was obtained via examination of the relationships between subscales and between the subscales and the Wiggins Content Scales. A consistent trend was identified for content subscales to relate most strongly to other content-congruent subscales and scales. Implications for the use of the content subscales and directions for future research were discussed.
Degree
Ph.D.
Subject Area
Psychotherapy
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.