Resolutions to interpretive dilemmas created by the minnesota multiphasic personality inventory 2 (MMPI-2): A reply to Strassberg

We discuss the interpretive dilemmas identified by Strassberg (1991) and propose to resolve these dilemmas by pointing out that some change has indeed been introduced in the MMPI-2 and that change is a necessary requisite for improvement. Changes in administration procedures used with the MMPI-2 normative sample should only improve the quality of the normative data; changes in the way T-scores were developed lead to minimal change in the profile but enable more accurate interpretation of differences between scales on an individual's profile; normative changes have a differential effect on the clinical scales and this is to be expected; and the problem of codetype congruence has been overestimated and overstated. We conclude that the change introduced in the MMPI-2 can only serve to improve the test.     

Effects of wealth on portfolios under various investment conditions

The present study addresses two major issues of portfolio selection tasks with one risky and one riskless alternative: (i) the effect of changes in capital on the proportion of capital put in savings, and (ii) the effect of the investment conditions (favorable vs unfavorable) on saving behavior. These two issues were investigated experimentally in a computer-controlled, discrete-time, multistage betting game in which each of 28 subjects had to make about 400 betting and savings decisions. The two major findings are: (i) the proportion of capital saved increases with the amount of capital on hand, and (ii) the proportion of capital saved decreases with practice when the investment conditions are favorable and increases with practice when they are unfavorable.     

How one gambles if one must: Effects of differing return rates on multistage betting decisions

In the multistage betting game (MBG), a decision maker (DM) is provided with some capital x which he is required to bet over m (m > 1) mutually exclusive and collectively exhaustive alternatives, each of which occurs with probability p_i (p_i > 0, i = 1,…, m; Σ_{i = 1}^mp_i = 1). If y_i is bet on alternative i (y_i ≥ 0, Σ_{i = 1}^my_i = x) and alternative i obtains, the DM's capital for the next stage is y_ir_i, (r_i > 0). The MBG lasts until either the DM loses his capital or N stages elapse, whichever comes first. Each of six subjects participated in six sessions consisting of several hundred 3-alternative MBG stages. A within-subject design assigned negative expected value (EV) bets to the first three sessions and positive EV bets to three more sessions. Significant effects were found due to return rate, capital size, homogeneous runs of either wins or losses, and individual differences. Four maximization of expected utility and two minimization of risk models were presented and tested. A modified logarithmic utility model is proposed, which provides the best fit to the data. The implications of the results and directions for further research are briefly discussed.     

Experimental tests of the mean-variance model for portfolio selection

Statistically knowledgeable male and female undergraduate students participated in 40 portfolio selection problems with monetary payoff contingent on performance. The portfolio selection task included two independent risky assets with normally distributed returns. It provided access to information about previous returns, allowed borrowing and lending at a fixed interest rate, and forced on each decision period a choice between the two risky assets. The findings show a high percentage of inefficient mean-variance portfolios which does not decrease with practice, a high rate of requests for useless information, a large frequency of switches between the two risky assets, and sequential dependencies. Theoretical and practical implications of the findings are briefly discussed.     

Computerized adaptive personality testing: a review and illustration with the MMPI-2 Computerized Adaptive Version

Computerized adaptive testing in personality assessment can improve efficiency by significantly reducing the number of items administered to answer an assessment question. Two approaches have been explored for adaptive testing in computerized personality assessment: item response theory and the countdown method. In this article, the authors review the literature on each and report the results of an investigation designed to explore the utility, in terms of item and time savings, and validity, in terms of correlations with external criterion measures, of an expanded countdown method-based research version of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), the MMPI-2 Computerized Adaptive Version (MMPI-2-CA). Participants were 433 undergraduate college students (170 men and 263 women). Results indicated considerable item savings and corresponding time savings for the adaptive testing modalities compared with a conventional computerized MMPI-2 administration. Furthermore, computerized adaptive administration yielded comparable results to computerized conventional administration of the MMPI-2 in terms of both test scores and their validity. Future directions for computerized adaptive personality testing are discussed.     

Empirical correlates of the MMPI-2 Restructured Clinical (RC) Scales in mental health, forensic, and nonclinical settings: an introduction

We introduce 3 studies of the empirical correlates of the MMPI-2 Restructured Clinical (RC) Scales: a study by Arbisi, Sellbom, and Ben-Porath (2008/this issue) that expands the range of correlates of the RC scale in mental health settings; an investigation by Sellbom, Ben-Porath, Baum, Erez, and Gregory (2008/this issue) of the empirical correlates of the scales in a forensic setting; and a study by Forbey and Ben-Porath (2008/this issue) examining convergent and discriminant validities of the RC scale in a nonclinical setting. To serve as a general introduction to the 3 new empirical studies presented in this special section, we begin with a review of the existing literature on the RC scales and briefly describe these studies.     

Correlates of MMPI–A Scales in Acute Psychiatric and Forensic Samples

The purpose of this study was to expand the empirical basis for interpretation of the Minnesota Multiphasic Personality Inventory–Adolescent (MMPI–A; Butcher et al., 1992). Participants were 157 boys from a forensic setting and 197 girls from an acute psychiatric inpatient setting. Criterion variables were identified from sources such as psychiatrist report, parent report, and psychosocial history. Results generally support the construct validity of MMPI–A scales. Scales measuring internalizing problems were more highly correlated with criterion measures of internalizing behaviors than measures of externalizing behaviors, whereas scales measuring externalizing problems were more highly correlated with externalizing variables than with internalizing criteria. Implications of this study include an expanded empirical foundation for interpretation of the MMPI–A, greater understanding of the constructs it measures, and evidence supporting the generalizability of these constructs across settings.