Response variable hypotheses in the multivariate analysis of variance.

Es using multivariate analysis of variance (MANOVA) usually want to analyze effects separately for each response variable after rejecting a null hypothesis of multivariate dispersion. From the standpoint of the multivariate general linear model, 4 measures of importance for response variables are discussed: univariate F statistic for each response, standardized canonical coefficient for each response, contribution to the MANOVA test criterion by each response, and simultaneous confidence intervals on estimates of treatment effects on each response. Artificial data are presented to illustrate problems in using these measures. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On choosing a test statistic in multivariate analysis of variance.

Users of multivariate analysis of variance must choose which of several available test statistics to employ as a generalization of the usual univariate F statistic. A review of statistical literature concerning the power and robustness of the 4 most promising tests leads to the recommendation of K. C. Pillai's (1955) and M. S. Bartlett's (1939) trace statistic for general use. A survey of recent experimental reports revealed that psychologists have been using a 2nd best statistic and that they have frequently failed to specify their statistic to let readers judge its appropriateness. To facilitate increased use of the Pillai-Bartlett statistic, information is given concerning computation, the availability of significance tables, and a convenient F approximation. (45 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reexamination of a plea for multivariate analyses.

Re-examines 2 issues raised in an article by M. R. Leary and E. M. Altmaier (see record 1981-02539-001) proposing MANOVA as a solution to the problem of inflated Type I error. Guidelines are discussed for choosing an overall MANOVA test statistic and post hoc tests that determine the dependent variable or variables responsible for any significant effects. It is concluded that guidelines based on recent comparisons of the various test statistics be used by researchers rather than advice found in basic textbooks. A discussion of the power of MANOVA concludes that although MANOVA may under some conditions reduce the chances of detecting significance, it is powerful for detecting legitimate experimental effects that are spread across more than one dependent variable. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What do you do when asked to answer humorously?

250 12th-grade and male Jewish and Arab students were given a modified version of the Rosenzweig Picture-Frustration Study. They were asked to answer this questionnaire twice: (a) ordinarily (as if they were present in the situation) and (b) humorously (as amusingly as possible). When ordinary and humorous answers were compared, it was found that humorous answers contained more expressions of high aggression and fantasy denials. Ordinary answers contained low aggression and rational denials. Humorous answers manifested the use of special techniques as specified by Freud: displacement, representation by the opposite, play on words, absurdity, and fantasy. Results show that Ss applied clear rules when answering with humor. They used more aggression, more sex, and more fantasy and they used Freud's techniques as if they had read his writings. Results are discussed by contrasting incongruity explanations with motivational explanations. Results do not support Freud's cathartic hypothesis. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What to do? The effects of discrepancies, incentives, and time on dynamic goal prioritization.

This study examined factors that influence the dynamic pursuit of multiple goals over time. As hypothesized, goal-performance discrepancies were significantly related to subsequent time allocation. Greater distance from a given goal resulted in greater time subsequently allocated to that goal. In addition, the incentives offered for goal attainment determined the relative influence of discrepancies for each goal. When the incentives for each goal were equivalent, progress toward each goal exhibited equal influence, with greater time allocated to whichever goal was furthest from completion at the time. However, with an incentive available for only 1 of the 2 goals, time allocation was largely determined by progress toward the rewarded goal. Likewise, when incentives for each task differed in their approach-avoidance framing, progress toward the avoidance-framed goal was a stronger predictor of subsequent allocation than was progress toward the approach-framed goal. Finally, the influence of goal-performance discrepancies differed as a function of the time remaining for goal pursuit. The implications for future work on dynamic goal prioritization and the provision of performance incentives are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Smoking and pregnant teens. What nurses can do to help

Valerie is a typical 17-year-old girl--active in high school sports and very social with a large group of friends. She became sexually active when she was 15, and, like many of her friends, occasionally smoked at parties or after school. After she missed two periods in a row, Valerie thought she should call a health care provider. When she learned she was pregnant, she was forced to face another challenge: could she quit smoking?     

Increase in power through multivariate analyses

Analysis of MHC class I and class II polymorphism, as well as data from other polymorphic systems (non-MHC lymphocyte alloantigen, blood groups systems, biochemical polymorphisms and microsatellite loci), was used to characterize the extent and distribution of the genic polymorphism of Kladruber horses. A breed-characteristic distribution of the MHC polymorphism was found. The repertoire of defined MHC class I specificities was restricted, especially in the grey subpopulation and in stallions, but a high frequency of blanks suggests the possible existence of undetected specificities. Despite the small population size and a relatively high degree of inbreeding, high heterozygosity in MHC haplotypes has been conserved. The extent of polymorphism and the degree of heterozygosity in other loci were also relatively high. A comparison of the two existing subpopulations, grey and black, at all the loci tested, including RAPD markers, characterized them as genetically distinct, although clearly related. The genetic distances between them were of the same order of magnitude as between distinct breeds. The results may be useful in defining short-term and long-term breeding policy within the breed and for further studies of associations with disease and other traits.     

What to do when your back is in pain

Trinitrotoluene (TNT) effect on the eyes of 250 miners was studied. The length of service of the investigated group varied from one to twenty years. The specific trinitrotoluene cataract of various stages was observed in 54.7% of the examinees. The authors assume that the lens changes depend on the length of service and on the TNT concentrations in the body after predominant skin penetration.     

Toward a career psychology of women: What do we know? What do we need to know?

Reviews what is presently known in salient areas of theory, knowledge, attitudes, and techniques and outlines the various areas of expertise that should be required of those engaged in career counseling with women. Theories of career choice, career maturity, and achievement motivation are discussed, and socio-psychological information about women and the work world, sex bias in vocational interest inventories, and the reliability and relevance of career information about women are surveyed. Counselor biases and influences of client socialization reflect stereotypic attitudes limiting career choices by women. It is recommended that courses on the special needs of women be included in the training of career counselors and that counselors should actively encourage women to examine their positions and needs and to consider nontraditional careers. The goal of this is that career choice should reflect the client's optimal potential. (4 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comment on Olson: Choosing a test statistic in multivariate analysis of variance.

Questions C. L. Olson's (see record 1976-25211-001) claim that the Pillai-Bartlett statistic (V) is superior to the Wilks λ (W) and the Hotelling-Lawley trace (T) for general use in multivariate ANOVA because of much greater robustness against unequal covariance matrices. It is shown by a sampling of studies from the literature that the example Olson used to demonstrate superiority had extreme subgroup variance differences, which occur very infrequently. For subgroup variance differences much more likely to occur, it is shown that the actual Type I error rates for V, T, and W are very similar. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bias/variance analyses of mixtures-of-experts architectures

This article investigates the bias and variance of mixtures-of-experts (ME) architectures. The variance of an ME architecture can be expressed as the sum of two terms: the first term is related to the variances of the expert networks that comprise the architecture and the second term is related to the expert networks' covariances. One goal of this article is to study and quantify a number of properties of ME architectures via the metrics of bias and variance. A second goal is to clarify the relationships between this class of systems and other systems that have recently been proposed. It is shown that in contrast to systems that produce unbiased experts whose estimation errors are uncorrelated, ME architectures produce biased experts whose estimates are negatively correlated.     

What to do if IDPR comes to your office. Illinois Department of Professional Regulation

What should you do if the Illinois Department of Professional Regulations comes to your door? First thing, don't panic. Second thing, call your attorney.     

What do people want to know about psychotherapy?

Assessed information people want about psychotherapy, and the effect of prior exposure to a written consent form on preferences for information. 108 adults, half of whom had received a written informed consent form, answered an open-ended question about their preferences for information. Ss most frequently asked for information about the therapist, especially personal characteristics. Least frequently cited were items concerning appointments, alternatives, and confidentiality. Ss exposed to the written consent form were more likely to ask about confidentiality and financial arrangements and, if they had not had previous therapy experience, were less likely to ask about personal characteristics of the therapist. (PsycINFO Database Record (c) 2010 APA, all rights reserved)