Choosing Between Parametric and Nonparametric Tests

A fundamental analysis decision confronting researchers in psychology and education is the choice between parametric and nonparametric tests. Despite the statistical and substantive implications of this important decision, many researchers unerringly employ parametric tests and thus ignore the advantages of their nonparametric counterparts. One justification for this behavior has been the absence of guidelines for choosing between these procedures. A second has been the lack of a comprehensive nonparametric test that is computationally manageable. In this article, the author discusses several statistical and substantive criteria that can be used to choose between parametric and nonparametric tests. A non-parametric test capable of testing a number of statistical hypotheses using existing computer packages is also presented. Recommendations are made encouraging researchers to routinely use nonparametric tests in their data analytic work.     

Effect of social support on the stress-burnout relationship

Business organizations have become interested in recent years in the role of social support in reducing the negative effect of stress. The purpose of this research is to examine the effects of two types of social support (i.e., job and life support) on the relationships between job and life stress and burnout. Participants consisted of 270 males and 254 females. For both males and females job stress and life stress correlate positively with burnout, while job and life support were negatively correlated with burnout. The hypothesis that social support would moderate stress-burnout relationships was not supported. Neither job support nor life support moderated job stress or life stress-burnout relationships. Females exhibited significantly higher levels of burnout, job stress, and life stress than males; however, there was no difference between males and females in the amount of social support received.     

A longitudinal study of the psychosocial impact of stroke on primary support persons

We investigated longitudinally the effects of a stroke on the social support systems and well-being of the patient's primary support person, both acutely and as the condition stabilized. Individuals who had suffered a first stroke and a primary support person participated in two waves of data collection, carried out in 6-month intervals beginning 7 weeks after the stroke. Our data show that the prevalence of depressive symptoms is from 2 1/2 to 3 1/2 times higher than rates found among representative samples of middle-aged and elderly populations. Mean level of depression did not change over time, although level of optimism declined significantly. Multiple regression analyses showed that levels of depression and perceived burden in support persons are highly related to aspects of the stroke such as its severity, and that demographic variables such as age and income play a relatively minor role in attenuating these relations in the acute adjustment phase. However, from 7 to 9 months after the stroke, well-established demographic variables such as health, income, and age were significant predictors of depression. Individuals who were older and who had good health and higher incomes were least depressed.     

Treatment recommendations for mentally disordered offenders: More than roulette?

Clinical judgments on the treatability and prognosis of mentally disordered offeenders (MDO) may strongly influence legal dispositions and the availability of treatment resources. This study examined 1,238 discharge summaries for MDOs referred for court assessments. Psychiatrists evidenced marked variability in how often they recommended treatment and how frequently they judged patients to have a poor prognosis. Two logit analyses suggested that diagnosis and consultation by other clinicians were associated with (a) treatment recommendations (i.e., Axis I diagnosis and social work consultations) and (b) prognosis (i.e., Axis II diagnosis and psychology consultations).     

Forgetting of pictures over a long retention interval in young and older adults

Young and older adults were presented with pictures for study. Their recognition of the information was tested at five retention intervals: immediately, and 48 hr, 1 week, 2 weeks, and 4 weeks later. The main finding of interest was that picture recognition did not show an age-related decline until the 1-week retention interval.     

Different patterns of cognitive slowing produced by Alzheimer's disease and normal aging

Aging has previously been shown to produce a generalized proportional slowing of all cognitive operations. In contrast, the present results suggested that Alzheimer's disease produces a disproportionate reduction in the speed with which patients carry out one or more mental operations. The tasks that demented patients found particularly difficult involved either a self-directed search of their lexicon or the use of familiarity information.     

Structural integration of the Affect Balance Scale and the Life Satisfaction Index A: race, sex, and age differences

In this research we examined race, sex, and age differences in the factorial structure of Liang's (1985) model of subjective well-being that integrates the Affect Balance Scale and the Life Satisfaction Index A. In particular, we viewed the covariance structure of the items as a function of several parameter matrices. We analyzed the factorial invariance by testing hypotheses involving the equivalence constraints of one or more parameter matrices with regard to the following: White and Black subsamples, men and women, and the young-old and the old-old. Data for the research came from the 1974 Harris National Council on Aging Survey, Myths and Reality of Aging in America. Analysis of covariance structures, or LISREL, was used to assess the factorial invariance. Replicated race differences were found in the factorial structure, but sex and age differences were not found. Consistent race differences were found for the second-order factor loadings for negative affect.     

Effects of male social status on reproductive success and on behavior in mice (Mus musculus)

Differences in reproduction as well as in behavior in the presence of females were evaluated according to dominant and subordinate male rank in albino mice, in the temporary absence of each male's antagonist. Dominant males reproduced more successfully than subordinate males. Subordinate males were generally inactive, except for displacement activities, during the first 15 min they were exposed to female partners. These findings suggest that mechanisms other than male-male interference or mating order may be operating or influencing behavior and reproductive results.     

Age analysis of cognitive-behavioral group therapy for chronic pain outpatients

This study explored the effectiveness, in terms of age of the client, of a 10-week cognitive-behavioral group therapy (stress inoculation training) for chronic pain. A total of 69 outpatients between the ages of 27 and 80 (M = 52.74 years, SD = 14.40) with diverse types of chronic pain were assigned randomly to immediate or wait-list-delayed therapy. Self-report measures of pain, activities, coping, and the use of medications and other physical pain control techniques were obtained at baseline, during therapy, and at 1- and 6-month follow-up. Treatment decreased the degree to which pain interfered with activity, increased ability to cope with pain, and decreased use of some medications and other physical treatments. It had little effect on perceived pain intensity. Gains were maintained through 6-month follow-up. Age was unrelated to outcome. Stress inoculation training appears to be an effective method of ameliorating the interference of chronic pain with the daily activities of life for adults of all ages.     

Daily stress and anxiety and their relation to daily fluctuations of symptoms in asthma and chronic obstructive pulmonary disease (COPD) patients

Although stress and anxiety have long been assumed to play an exacerbatory role in asthma, no study has systematically documented that daily exacerbations of asthma symptoms are related to stress and/or anxiety. In this study, 24 airways obstruction patients (12 asthmatics and 12 chronic obstructive pulmonary disease patients) were instructed to monitor the severity of daily respiratory symptoms. In addition, subjects recorded their daily anxiety level and the number and perceived impact of daily stressors. The results showed that although there were differences between high- and low-stress days for both groups, there were no differences between groups on symptom severity or between high- and low-anxiety days, as measured by the State-Trait Anxiety Inventory (STAI). Thus, although the number and impact of daily stressors were found to be directly associated with the severity of asthma symptoms, anxiety does not appear to have a direct role in the exacerbation of asthma. The findings failed to support the anxiety theory of asthma but provided an explanation for the poor results obtained in previous treatment studies which employed anxiety management with asthmatics.