An update on ‘a comparative study of tests for homogeneity of variance’

Tests for equality of variances using independent samples are widely used in data analysis. Conover et al. [A comparative study of tests for homogeneity of variance, with applications to the outer continental shelf bidding data. Technometrics. 1981;23:351–361], won the Youden Prize by comparing 56 variations of popular tests for variance on the basis of robustness and power in 60 different scenarios. None of the tests they compared were robust and powerful for the skewed distributions they considered. This study looks at 12 variations they did not consider, and shows that 10 are robust for the skewed distributions they considered plus the lognormal distribution, which they did not study. Three of these 12 have clearly superior power for skewed distributions, and are competitive in terms of robustness and power for all of the distributions considered. They are recommended for general use based on robustness, power, and ease of application.     

Some exact tables for the squared ranks test

Since the squared ranks test was first proposed by Taha in 1964 it has been mentioned by several authors as a test that is easy to use, with good power in many situations. It is almost as easy to use as the Wilcoxon rank sum test, and has greater power when two populations differ in their scale parameters rather than in their location parameters. This paper discuss the versatility of the squared ranks test, introduces a test which uses squared ranks, and presents some exact tables     

Parental Depression and Child Outcomes: The Mediating Effects of Abuse and Neglect

Using longitudinal data on 1,813 children and parents from a nationally representative child‐welfare sample, National Survey of Child and Adolescent Well‐Being (NSCAW), this study investigated physically abusive and neglectful parenting as mediating the effects of parent depression on child mental health by developmental stage. Findings from latent growth models indicated that parental depression had a significant impact on child outcomes for all youths, but of the 2 types of parenting behaviors, only neglectful parenting mediated the relationship for preschool and school‐aged children. Neither parenting behavior mediated the effects of parental depression for adolescents.     

Comparisons of the asymptotic efficiencies of two sample tests for discrete distributions

The asymptotic efficiencies are computed for several popular two sample rank tests when the underlying distributions are Poisson, binomial, discrete uniform, and negative binomial The rank tests examined include the Mann-Whitney test, the van der Waerden test, and the median test. Three methods for handling ties are discussed and compared. The computed asymptotic efficiencies apply also to the k-sample extensions of the above tests, such as the Kruskal-Wallis test, etc.     

A nonparametric confidence interval for slope based on spearman's rho

An algorithm is presented for computing an exact nonparametric interval estimate of the slope parameter in a simple linear regression model. The confidence interval is obtained by inverting the hypothesis test for slope that uses Spearman's rho. This method is compared to an exact procedure based on Kendall's tau. The Spearman rho procedure will generally give exact levels of confidence closer to desired levels, especially in small samples. Monte carlo results comparing these two methods with the parametric procedure are given     

On some alternative procedures using ranks for the analysis of experimental designs

The analysis of data from eseperisental designs is often hampered by the lack of more than one procedure available for the analysis, especially when that procedure is based on assumptions which do not apply in the situation at hand. In this paper tvo classes of alternative procedures are discussed and compared, One is the aligned ranks procedure which first standardises the data by subtracting an appropriate estimate of location, then replaces the data with ranks t and finally uses an appropriate test statistic which has asymptotically a chi-square distribution The second procedure is the rank transform which first replaces all of the data with the ranks, and then employs the usual parametric methods, but computed on the ranks instead of the data Some Monte Carlo simulations for a test of interaction in a two way layout with replication enable the robustness and pover of these tvo methods to be compared with the usual analysis of variancs.     

The quality of mother‐adolescent disclosure: Links with predictors and adolescents’ sociomoral outcomes

Previous work on adolescents’ disclosure has focused on the frequency of disclosure to parents, but not the quality of that disclosure. Therefore, there is a need to examine factors that predict the quality of adolescents’ disclosure, as well as the consequences of the quality for adolescents’ outcomes. In this study, 100 adolescents (M age = 14.27 years; 57 girls; 70.7% White, European American) disclosed to mothers a recent past event in which they felt excluded; the videotaped and transcribed conversations were rated for indices of the quality of disclosure (i.e., the quality of elaboration and emotion discussed). Adolescents completed measures of sociomoral behavior and parental warmth and mothers completed measures of their moral identity, circle of moral regard, and moral socialization. The quality of adolescents’ disclosure was related to adolescents’ sociomoral outcomes (including prosocial behaviors, empathy, and sociability). Adolescents’ disclosure quality was predicted by gender and by aspects of mothers’ moral sophistication. Findings highlight the importance of high‐quality self‐disclosure by adolescents for promoting adolescents’ moral development, potentially because such disclosure gives parents the opportunity to help adolescents cope with challenging peer experiences potentially through emotion coaching and problem‐solving. Moreover, the findings are novel because they highlight how maternal moral processes might promote adolescents’ disclosure.