Tests of serial independence based on Kendall's process

The authors propose new rank statistics for testing the white noise hypothesis in a time series. These statistics are Cramér‐von Mises and Kolmogorov‐Smirnov functionals of an empirical distribution function whose mean is related to a serial version of Kendall's tau through a linear transform. The authors determine the asymptotic behaviour of the underlying serial process and the large‐sample distribution of the proposed statistics under the null hypothesis of white noise. They also present simulation results showing the power of their tests.     

Early Word Segmentation by Infants and Toddlers With Williams Syndrome

This study tested the ability of English infants and toddlers with Williams syndrome to segment, that is, to extract from fluent speech, bisyllabic nouns that had either a strong–‐weak stress pattern (predominant in English), or a weak–‐strong stress pattern. The testing procedure was the same for both types of words: Children were familiarized with instances of isolated nouns, and then tested on their recognition of these nouns embedded in passages. In English, typically developing infants start segmenting strong–‐weak nouns by 7.5 months of age, and weak–‐strong nouns by 10.5 months. Our clinical population was able to segment strong–‐weak nouns, but failed, despite chronological ages above 15 months, to segment weak–‐strong words. These results suggest that the development of word segmentation is seriously delayed in Williams syndrome. This deficit in early phonological processing may contribute to a fuller understanding of the late lexical onset in this population, a phenomenon that had hitherto only been explained in terms of cognitive and semantic deficits.     

Factors That Influence Persistence in Science and Engineering Career Aspirations

The author investigated students' persistence regarding career aspirations in science and engineering (SE) professional careers as a function of race and sex. In a nationally representative sample of 8th graders, persistent racial minority and female students were compared with nonpersistent racial minority and male students regarding their self‐concept, parental involvement, socioeconomic status, and academic achievement. Men were more likely than women to persist in SE career aspirations. Persistent students scored higher than did nonpersistent students on all of the variables studied. Academic proficiency and math self‐efficacy were 2 of the strongest predictors of persistence in SE careers.     

Bayesian methods for generalized linear models with covariates missing at random

The authors propose methods for Bayesian inference for generalized linear models with missing covariate data. They specify a parametric distribution for the covariates that is written as a sequence of one‐dimensional conditional distributions. They propose an informative class of joint prior distributions for the regression coefficients and the parameters arising from the covariate distributions. They examine the properties of the proposed prior and resulting posterior distributions. They also present a Bayesian criterion for comparing various models, and a calibration is derived for it. A detailed simulation is conducted and two real data sets are examined to demonstrate the methodology.     

Changes in Support From Confidants,Children, and Friends Following Widowhood

This paper examines the extent to which widowhood affects changes in (a) the availability of a confidant, (b) emotional support from children, and (c) emotional support from friends/relatives both 6 and 18 months after spousal loss. Analyses are based on data from the Changing Lives of Older Couples, a prospective study of 1,532 married individuals aged 65 and older. Compared to married persons, widowed persons are less likely to have a confidant, yet they receive greater support from children, friends, and relatives, controlling for support prior to widowhood. The findings suggest that, although close social relationships may remain stable in the course of normal aging, stressful events such as widowhood may bring forth both losses and gains in social support.     

Nonstandard Employment in the Nonmetropolitan United States*

Abstract We examine the prevalence of nonstandard employment in the nonmetropolitan United States using the Current Population Survey Supplement on Contingent Work (1999 and 2001). We find that nonstandard work is more prevalent in nonmetropolitan than in central city or suburban areas. Logistic regression models controlling for sociode‐mographic and work characteristics, show that nonmetropolitan workers experience higher odds of nonstandard employment than central city or suburban workers. Variations in industrial and occupational structures in nonmetro and metro areas do not explain residential differences in nonstandard work. We also estimate the odds of employment in each of the three components of nonstandard work: contingent work, part‐time, and varied hour work. Nonmetropolitan workers are more likely than central city and suburban workers to be employed in contingent or varied hour work. The benefits and wages of nonstandard work are lower than for standard work across residence areas. The results highlight the importance of understanding nonstandard work and the components of nonstandard work, particularly when considering the nature of work across industries, occupations, and residence.     

Career Counseling in a Volatile Job Market: Tiedeman's Perspective Revisited

This article explores implications of Tiedeman's original theory for career counselors. Some components of the theory seem to be compatible with existing volatile job market conditions. Notions of career path recycling, development in reverse, nonlinear progress, and parallel streams in career development are explored. Suggestions are made for counseling interventions and future research using this perspective.     

School's out! Why earlier among children of lone parents?

The aims of this population-based study were to analyse educational attainment at ages 24–25 among children of lone parents in comparison with children living with two biological parents, to increase understanding of the factors that seem to be of major importance in increased risks of lower educational achievement and to examine how the life circumstances of non-custodial parents influence possible differences. We found that children who grew up with only one parent showed lower educational attainment than did children in two-parent families. Poorer educational performance on the part of the offspring of lone parents can be explained to a large extent by socio-economic disadvantage, especially a lack of economic resources. However, achievement varies according to cause of lone parenting, and findings strongly indicate that adjusting solely for custodial parents' circumstances may lead to under-estimation of the relationship. Lone parenting seems to have a more detrimental effect on girls' education, and also within groups of children with highly educated parents than among those with a relatively low level of education.     

Control charts for monitoring the median in non-negative asymmetric data

Statistical Methods & Applications - Control charts are commonly used for monitoring the mean of processes. However, there are practical applications in which asymmetric data are the standard....