Taxometrics in Psychopathology Research: An Introduction to Some of the Procedures and Related Methodological Issues.

This article introduces a special section on the use of taxometrics to examine the categorical versus the dimensional structure of various forms of psychopathology. Paving the way into the special section, this introduction briefly describes 3 taxometric methods--mean above minus below a sliding cut (MAMBAC), maximum covariation (MAXCOV), and maximum eigenvalue (MAXEIG)--and discusses possible threats to statistical conclusion validity that often emerge when such techniques are applied in psychopathology research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Latent structure of anxiety: Taxometric exploration.

Taxometrics is a statistical tool that can be used to discern categories from continua. Taxometric analyses (MAXCOV and MAXEIG) were conducted in a large nonclinical sample (N=1,215) to determine whether extreme anxiety forms a distinct psychopathological category, an anxiety taxon. Anxiety was operationalized with self-report measures of subjective anxiety, anxious cognitive style, physiological arousal, and anxiety-related impairment. Procedures consistently identified a taxon with a prevalence of approximately 11%. Examination of the taxon's convergent and discriminant validity revealed that it reflects general distress rather than physiological arousal. Taxon membership showed some evidence of incremental validity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychopathic, not psychopath: Taxometric evidence for the dimensional structure of psychopathy.

Although psychopathy is frequently regarded as qualitatively distinct from other conditions, relatively little research has examined whether psychopaths represent a distinct class of individuals. Using a sample of 876 prison inmates and court-ordered substance abuse patients who were administered the Psychopathy Checklist-Revised (R. D. Hare, 2003), the authors examined the latent structure of psychopathy using several taxometric procedures developed by Meehl and colleagues (P. E. Meehl & L. J. Yonce, 1994; N. G. Waller & P. E. Meehl, 1998). The results across these procedures offer no compelling support for the contention that psychopathy is a taxonic construct and contradict previous reports that psychopathy is underpinned by a latent taxon. The authors discuss the theoretical, public policy, and practice-level implications of these findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dimensionality assessment of ordered polytomous items with parallel analysis.

Parallel analysis (PA) is an often-recommended approach for assessment of the dimensionality of a variable set. PA is known in different variants, which may yield different dimensionality indications. In this article, the authors considered the most appropriate PA procedure to assess the number of common factors underlying ordered polytomously scored variables. They proposed minimum rank factor analysis (MRFA) as an extraction method, rather than the currently applied principal component analysis (PCA) and principal axes factoring. A simulation study, based on data with major and minor factors, showed that all procedures consistently point at the number of major common factors. A polychoric-based PA slightly outperformed a Pearson-based PA, but convergence problems may hamper its empirical application. In empirical practice, PA-MRFA with a 95% threshold based on polychoric correlations or, in case of nonconvergence, Pearson correlations with mean thresholds appear to be a good choice for identification of the number of common factors. PA-MRFA is a common-factor-based method and performed best in the simulation experiment. PA based on PCA with a 95% threshold is second best, as this method showed good performances in the empirically relevant conditions of the simulation experiment. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Taxometric and factor analytic models of anxiety sensitivity: Integrating approaches to latent structural research.

This study represents an effort to better understand the latent structure of anxiety sensitivity (AS), as indexed by the 16-item Anxiety Sensitivity Index (ASI; S. Reiss, R. A. Peterson, M. Gursky, & R. J. McNally, 1986), by using taxometric and factor-analytic approaches in an integrative manner. Taxometric analyses indicated that AS has a taxonic latent class structure (i.e., a dichotomous latent class structure) in a large sample of North American adults (N = 2,515). As predicted, confirmatory factor analyses indicated that a multidimensional 3-factor model of AS provided a good fit for the AS complement class (normative or low-risk form) but not the AS taxon class (high-risk form). Exploratory factor analytic results suggested that the AS taxon may demonstrate a unique, unidimensional factor solution, though there are alternative indications that it may be characterized by a 2-factor solution. Findings suggest that the latent structural nature of AS can be conceptualized as a taxonic latent class structure composed of 2 types or forms of AS, each of these forms characterized by its own unique latent continuity and dimensional structure. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Paranoid personality has a dimensional latent structure: Taxometric analyses of community and clinical samples.

Although paranoid personality is one of the most commonly diagnosed personality disorders and is associated with numerous negative life consequences, relatively little is known about the structural properties of this condition. This study examines whether paranoid personality traits represent a latent dimension or a discrete class (i.e., taxon). In Study 1, the authors conducted taxometric analyses of paranoid personality disorder criteria in a sample of 731 patients participating in the Collaborative Longitudinal Study of Personality Disorders project (Gunderson et al., 2000) who had been administered a semistructured diagnostic interview for personality disorders according to criteria of the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994). In Study 2, the authors conducted parallel analyses of the Paranoia scale of the Personality Assessment Inventory (PAI; L. C. Morey, 2007), using data from the PAI community and clinical normative databases. Analyses across both self-report and interview-based indicators offered compelling support for a dimensional structure. Additionally, analyses of external correlates in these data sets suggested that dimensional models demonstrated stronger validity coefficients with criterion measures than did dichotomous models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of estimation methods on making trait-level inferences from ordered categorical items for assessing psychopathology.

In assessments of attitudes, personality, and psychopathology, unidimensional scale scores are commonly obtained from Likert scale items to make inferences about individuals' trait levels. This study approached the issue of how best to combine Likert scale items to estimate test scores from the practitioner's perspective: Does it really matter which method is used to estimate a trait? Analyses of 3 data sets indicated that commonly used methods could be classified into 2 groups: methods that explicitly take account of the ordered categorical item distributions (i.e., partial credit and graded response models of item response theory, factor analysis using an asymptotically distribution-free estimator) and methods that do not distinguish Likert-type items from continuously distributed items (i.e., total score, principal component analysis, maximum-likelihood factor analysis). Differences in trait estimates were found to be trivial within each group. Yet the results suggested that inferences about individuals' trait levels differ considerably between the 2 groups. One should therefore choose a method that explicitly takes account of item distributions in estimating unidimensional traits from ordered categorical response formats. Consequences of violating distributional assumptions were discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

To touch or not to touch.

Argues that physical touch as part of psychodynamic psychotherapy is appropriate and useful under limited circumstances. However, the decision is to be based on a careful evaluation of the state of the patient. It is proposed that the distinction between regression and nondevelopment offers a meaningful rationale in the use of touching in psychotherapy. The therapist working with patients toward greater autonomy and characterological change may restrain the touching procedures with the regressed patient, whereas the therapist may consider the utility of touch with the patient suffering from arrested development. Three case illustrations are included in which the patient(s) initiated the contact. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

To read or not to read.

Criticizes the pendatry, pomposity, and obscurantism of much professional psychology writing and suggests 3 rules for improving its readability. (1) the language used should be as simple and direct as the information conveyed will permit, (2) the language used should not be so complex or technical that it implies greater profundity or scientific validity than can be supported by the material, and (3) the writer is obligated to write so that the reader not only may but must comprehend. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

To demand or not to demand.

Investigated whether adults believed that unconventionally dressed youths have values different from their own, using the Rokeach Value Survey. Findings from 29% of 510 Ss approached in shopping centers and at a public beach show that Ss did not perceive value differences. However, the conclusions are limited by the low response rate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

To tell or not to tell: The psychotherapist's dilemma.

Examines an ethical dilemma for professional psychologists treating potentially dangerous clients. The problems involved in predicting dangerousness are discussed as well as a number of possible interventions geared toward protecting the intended victim and society. Legal and ethical requirements to assess potential dangerousness, coupled with the "double agent" conflict and the tendency of mental health professionals to overpredict dangerousness, can adversely affect the therapist–client relationship and vitiate the treatment process. Legal and ethical issues confounding the course of action most effective for therapists to take to protect society and preserve individual rights are explored, and recommendations are proposed. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Malingering as a categorical or dimensional construct: The latent structure of feigned psychopathology as measured by the SIRS and MMPI-2.

The 6 nonoverlapping primary scales of the Structured Interview of Reported Symptoms (SIRS) were subjected to taxometric analysis in a group of 1,211 criminal and civil examinees in order to investigate the latent structure of feigned psychopathology. Both taxometric procedures used in this study, mean above minus below a cut (MAMBAC) and maximum covariance (MAXCOV), produced dimensional results. A subgroup of participants (n = 711) with valid Minnesota Multiphasic Personality Inventory-2 (MMPI-2) protocols were included in a second round of analyses in which the 6 nonoverlapping primary scales of the SIRS and the Infrequency (F), Infrequency-Psychopathology (Fp), and Dissimulation (Ds) scales of the MMPI-2 served as indicators. Again, the results were more consistent with dimensional latent structure than with taxonic latent structure. On the basis of these findings, it is concluded that feigned psychopathology forms a dimension (levels of fabrication or exaggeration) rather than a taxon (malingering-honest dichotomy) and that malingering is a quantitative distinction rather than a qualitative one. The theoretical and clinical practice implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

To be (objective) or not to be.

Comments that the power and the danger of E. E. Sampson's (see record 1994-17460-001) argument on identity politics are suggested by research on the psychology of women and the work done by R. K. White (1966) and by R. R. Holt and B. Silverstein (see record 1990-01052-001) on enemy images. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

To use or not to use: Clinicians' perceptions of telemental health.

Equal access to mental health services is necessary for healthy individuals and communities. However, due to geographical distances and other barriers, some clients cannot easily access mental health professionals. Technologies such as videoconferencing for clinical purposes (i.e., telemental health) may help to bridge these gaps to connect clients and clinicians at geographically diverse locations. However, despite its potential utility, telemental health has not been widely adopted in Canada. This study is an exploratory investigation into mental health professionals' attitudes toward telemental health, factors that affect the frequency with which they use this technology, and their perceptions of individual characteristics that make clients more or less suitable candidates for telemental health. This study has a particular focus on remote and rural and Operational Stress Injury (OSI) contexts. One hundred sixty mental health workers across Canada participated in an online survey, and 25 mental health workers from Operational Stress Injury clinics across Canada participated in in-person interviews. The data were examined using qualitative and quantitative analysis methods. Findings suggest that mental health workers have overall positive attitudes toward the use of telemental health—particularly for clients in remote and rural locations. Additionally, receiving training in telemental health, being in the mental health field for longer, and perceiving the technology as easy to use are associated with more frequent use of telemental health. Finally, clinicians reported specific client characteristics that they perceive to make some clients unsuitable candidates for telemental health. Implications of these findings and directions for future research are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Issues in Bioleaching: To Inoculate or not to Inoculate

Abstract

Two active bioleaching microbial strains were isolated from a zinc mineral sample. These bacteria isolates were grown on media containing sulfur or iron and reintroduced, individually or in combination, to the original mineral sample in controlled shake-flask bioleaching experiments. Uninoculated controls were included but no attempt was made to sterilize the solid material. On the contrary, growth of the same indigenous microorganisms was encouraged in the control flasks. Zinc was leached from both inoculated and uninoculated mineral at the same rate. The only difference was that the lag times before onset of leaching were shorter if active bacteria were present from the very beginning. In all cases, zinc was leached preferentially over iron. This difference was even more pronounced on leaching by sulfur-grown bacteria which did not extract iron to the same degree as iron-grown bacteria. When total leaching times required for 100% zinc extraction were compared, no statistically significant difference was observed between the inoculated and uninoculated tests. This conclusion may have some bearing on experimental and process design, when decisions must be made on whether to stimulate leaching by addition of extraneous bacteria or by fostering the proliferation of indigenous microorganisms.     

Within-subjects designs: To use or not to use?

Examines several factors pertinent to deciding whether a within- or between-Ss design should be employed for a research application. A general principle favoring within-Ss designs is the statistical efficiency afforded by removing S variance from error terms used to test treatment effects. Within-Ss designs, however, are often faulted for being subject to context effects of practice, sensitization, and carry-over that may limit interpretation of results. At the same time, between-Ss designs are not devoid of context effects, but rather have the context that a single treatment affords itself. Since ecological validity of results depends on the correspondence of the research context to the generalization context, within-Ss designs may be preferred when the generalization context includes the equivalent of several concurrent treatments. Procedures to minimize practice, sensitization and carry-over effects in within-Ss designs when they are not desired, and means of using these effects to advantage in research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

To agree or not to agree: Personal dissent amid social pressure to conform.

118 undergraduates expressed their opinions about 20 scenarios that described problems in human relations. Some Ss heard 3 confederates agreeing on a solution to each problem. Ss could either conform or they could dissent by choosing other available solutions or generating one of their own. From a self-presentational perspective, private self-consciousness, individuation, and self-esteem were predicted to be directly related to dissent and inversely related to conformity. Public self-consciousness, social anxiety, shyness, and self-monitoring were predicted to be directly related to conformity and inversely related to dissent. The relationship of self-concept to dissent and conformity was expected to be stronger when peer opinion was unanimous than when it was divided. Results support the predictions with the exception of the self-monitoring variable. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

To accept or not to accept: Referrals and the maintenance of boundaries.

Psychotherapists of all disciplines are confronted with many dilemmas in accepting or declining referrals from colleagues and patients, as well as referrals that may entail contact outside the office. The authors explore countertransference, confidentiality, boundaries, and ethics related to referral sources. Case material illustrates clinical dilemmas. Some suggestions are offered to help therapists critically examine the conscious and unconscious influences affecting their decisions about whether to accept a referral. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

To seek help or not to seek help: The risks of self-disclosure.

Investigations into the reasons why people seek counseling have, for the most part, focused on approach factors, those variables that are associated with a potential client's increased likelihood of seeking psychological services. The purpose of this research, however, is to explore the role of avoidance factors, those factors that are associated with a potential client's decreased likelihood of seeking services. Across 2 studies of primarily Caucasian college students (ns = 209 and 268, respectively). the results of simultaneous multiple regression analyses demonstrated that avoidance factors predict negative attitudes toward counseling as well as decreased intentions to seek counseling. Overall, results demonstrate that avoidance factors account for at least as much help-seeking variance as traditionally studied approach factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)