Evaluating the latent structure of the MMPI-2 F(p) scale in a forensic sample: A taxometric analysis.

Abstract

P. A. Arbisi and Y. S. Ben-Porath (1995) originally proposed that the Infrequency Psychopathology scale, F(p), be used as the final step in an algorithm to determine the validity of a Minnesota Multiphasic Personality Inventory-2 (MMPI-2) protocol. The current study used taxometric procedures to determine the latent structure of F(p) among examinees with profiles that would necessitate the interpretation of F(p) when using Arbisi and Ben-Porath's proposed algorithm. Participants included a subsample of 289 consecutively referred pretrial forensic examinees adjudicated incompetent to stand trial with high Infrequency (F) scale scores, thereby providing a sample that would be expected to have a high base rate of persons with bona fide psychopathology and persons with incentive to overreport psychopathology. Using MAMBAC and MAXEIG, F(p) produced a taxonic latent structure within the subgroup of examinees who obtained raw scores on F of greater than 17. These results support Arbisi and Ben-Porath's original proposal to use F(p) to identify a distinct subgroup of overreported MMPI-2 protocols within forensic psychiatric examinees with high elevations on F. Implications and suggestions for future research are provided.

Feigned neurocognitive deficit: Taxon or dimension?

“…The taxonic results obtained by Strong et al (2006) and Frazier et al (2007) clash with the dimensional results of and the current study. One possible explanation for these discrepant findings is that sampling or procedural factors created a pseudotaxon in the Strong et al (2006) and Frazier et al (2007) studies.…”

“…One possible explanation for these discrepant findings is that sampling or procedural factors created a pseudotaxon in the Strong et al (2006) and Frazier et al (2007) studies. A second possibility is that both sets of studies produced valid results but that contextual factors led to divergent outcomes.…”

“…Their results were limited by the fact that participants were nonforensic patients with little apparent motivation to simulate psychopathology. To address this limitation, Strong, Glassmire, Frederick, and Greene (2006) conducted a follow-up study with forensic examinees and uncovered evidence of a taxon using three indicators derived from the 27-item Fp scale. However, this study was disadvantaged by its small sample size and the absence of a multimethod approach (e.g., the inclusion of an interview-based measure of feigning).…”

Categories and Dimensions

“…Studying the latent structure of individual differences in response distortion would provide an empirical basis for selecting between these approaches. Similar problems in the realm of clinical assessment have led to taxometric studies (e.g., Strong et al, 2006) that suggest that symptom overreporting may be a categorical phenomenon.…”

“…For example, structural studies have found a categorical difference between respondents scoring at high and low levels on the Minnesota Multiphasic Personality Inventory (MMPI) infrequency scale F and the MMPI infrequency scale F(p); these scales are used to detect symptom overreporting (e.g., Strong, Glassmire, Frederick, & Greene, 2006). This finding suggests the utility of developing techniques to assign individuals to groups-those who do and those who do not overreport their symptoms -rather than assessing overreporting as a dimensional construct.…”