Methods for obtaining menstrual-cycle data in menstrual-synchrony studies: commentary on Schank (2001)

J. C. Schank (2001) claimed to identify 2 categories of error-measurement error and recall biases-in the methodology used in studies of menstrual synchrony. This commentary focuses on the 2nd of these, recall biases, and other errors that he argued may result from "allowing participants to fill out menstrual-cycle-onset calendars" (p. 3). J. C. Schank's detailed discussion of various types of recall biases is inappropriate and misleading given that the majority of menstrual-synchrony studies have used prospective menstrual calendars. The use of menstrual calendars is a well-accepted method in a number of research areas and demands little of participants. J. C. Schank questioned the validity of menstrual calendar data on the basis of assumptions about recall bias for which he had no evidence.     

The appropriateness of the MMPI-2 K correction

The extent to which the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) K scale serves as a suppressor variable that influences the validity of clinical scale scores was examined using 274 male and 425 female outpatients from a community mental health center and 105 male and 247 female clients from a university psychological clinic. Hierarchical regression analyses were performed with MMPI-2 K scale scores and clinical scale scores as predictors and therapist ratings as criteria. In most cases, the K scale did not act as a suppressor Optimal K weights were different from the traditional K corrections. In most instances, there were no significant differences between correlations of therapist ratings with K-corrected and uncorrected clinical scale scores. The results do not support the K scale as a suppressor variable in these settings, although additional research is needed in settings where higher levels of defensiveness are common.     

Missing data: our view of the state of the art

Statistical procedures for missing data have vastly improved, yet misconception and unsound practice still abound. The authors frame the missing-data problem, review methods, offer advice, and raise issues that remain unresolved. They clear up common misunderstandings regarding the missing at random (MAR) concept. They summarize the evidence against older procedures and, with few exceptions, discourage their use. They present, in both technical and practical language, 2 general approaches that come highly recommended: maximum likelihood (ML) and Bayesian multiple imputation (MI). Newer developments are discussed, including some for dealing with missing data that are not MAR. Although not yet in the mainstream, these procedures may eventually extend the ML and MI methods that currently represent the state of the art.     

Development of an Infrequency-Psychopathology scale for the MMPI-A: the Fp-A Scale

This article describes the development and initial validation of the Infrequency-Psychopathology scale, Fp-A, for the MMPI-A (Butcher et al., 1992). The scale parallels the Infrequency-Psychopathology scale, F(p), that has been developed for the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989). Results demonstrated that the 40-item Fp-A scale is superior to the F scale at discriminating between faking-bad and accurate reports of psychopathology, although the improvement over F was modest, particularly when compared to the improvement found for the F(p) scale. The difference seemed to reflect the superiority of the MMPI-A F scale to the MMPI-2 F scale. Even so, the findings suggest that the identification of overreporting on the MMPI-A could potentially be enhanced by using Fp-A as an adjunct to the F scale.     

Separate roles for executive and phonological components of working memory in mental arithmetic

A dual-task methodology was used to investigate the roles played by executive and phonological aspects of working memory in mental arithmetic. Experiment 1 showed that suppression of articulation impaired the ability to add a pair of briefly presented three-digit numbers. Suppression had no effect when the need to store temporarily was minimized by making the numbers visible throughout calculation. Experiment 2 showed that disrupting executive processes by requiring concurrent performance of a Trails task impaired the ability to add numbers that remained permanently visible. Performance on the Trails task deteriorated as the number of carry operations in the addition increased. Experiment 3 showed that this decline in Trails performance was not simply due to the extra time taken by carrying. These and other features of the results suggest that the carrying component of mental arithmetic places substantial demands on executive processes, whereas the need to retain problem information is met by the phonological loop. The results are consistent with an interpretation of executive processes according to which there is a limit on the capacity to inhibit strongly primed routine operations.     

On the interpretation of working memory span in adults

Experimental research into children's working memory span has shown that retention duration contributes substantially to span performance, while processing efficiency need not be related to concurrent memory load (Towse, Hitch, & Hutton, 1998). These findings have been used to argue for a model of working memory span that emphasizes time-based forgetting rather than the popular resource-sharing or tradeoff framework. The present paper considers whether adults perform working memory span tasks in a qualitatively different way. Data from reading span and operation span tasks show that adults' performance can be distinguished from that of children, but also that a task-switching model of working memory span can explain some important aspects of performance.     

Sampling Bias and Other Methodological Threats to the Validity of Health Survey Research

Data from a longitudinal occupational health survey of professional fire fighters were used to explore the potential impact of two types of methodological bias: sample selection and reactivity. No significant differences on demographic variables were observed between the group who first responded after a within-study change in survey administration format (Delayed) and respondents who had completed surveys since the study's inception (Initial). However, statistically significant differences in the study's 26 outcome measures provided some evidence that between-group differences did exist and that an administration format type of response bias was also potentially present. The effect sizes associated with the 37 observed significant differences ranged from small to medium. These results provide a context for a reexamination of standard techniques for the identification and interpretation of survey research biases. Methods are suggested to strengthen tests for selection bias and to minimize the impact of response biases.