A practical comparison of blinded methods for sample size reviews in survival data clinical trials

This paper presents practical approaches to the problem of sample size re-estimation in the case of clinical trials with survival data when proportional hazards can be assumed. When data are readily available at the time of the review, on a full range of survival experiences across the recruited patients, it is shown that, as expected, performing a blinded re-estimation procedure is straightforward and can help to maintain the trial's pre-specified error rates. Two alternative methods for dealing with the situation where limited survival experiences are available at the time of the sample size review are then presented and compared. In this instance, extrapolation is required in order to undertake the sample size re-estimation. Worked examples, together with results from a simulation study are described. It is concluded that, as in the standard case, use of either extrapolation approach successfully protects the trial error rates.     

Effect of Trajectories of Friends' and Parents' School Involvement on Adolescents' Engagement and Achievement

In a sample of 527 academically at‐risk youth, we investigated trajectories of friends' and parents' school involvement across ages 12–14 and the joint contributions of these trajectories to adolescents' age 15 school engagement and academic achievement. Girls reported higher levels of friends' and parents' school involvement than boys. Both parents' and friends' school involvement declined across ages 12–14. Combined latent growth models and structural equation models showed effects of the trajectories of friends' and parents' school involvement on adolescents' age 15 school engagement and academic achievement, over and above adolescents' prior performance. These effects were additive rather than interactive. Strategies for enhancing parent involvement in school and students' affiliation with peers who are positively engaged in school are discussed.     

Symposium: Neuroergonomics, technology, and cognition

This symposium describes collaborative research on neuroergonomics, technology, and cognition being conducted at George Mason University and the US Air Force Research Laboratory (AFRL) as part of the Center of Excellence in Neuroergonomics, Technology, and Cognition (CENTEC). Six presentations describe the latest developments in neuroergonomics research conducted by CENTEC scientists. The individual papers cover studies of: (1) adaptive learning systems; (2) neurobehavioral synchronicity during team performance; (3) genetics and individual differences in decision making; (4) vigilance and mindlessness; (5) interruptions and multi-tasking; and (6) development of a simulation capability that integrates measures across these domains and levels of analysis.     

Animals and anomalies: an analysis of the UK veterinary profession and the relative lack of state reform

The sociology of professions literature would predict that the contemporary state would not allow groups to continue unregulated or unreformed. However, this is indeed the case with the UK veterinary profession, with legislation dating back to 1966. Using an interdisciplinary analysis of published literature and reports, this paper assesses whether wider social, political and ethical dynamics can better explain this intriguing anomaly. We conclude with critical implications for the sociology of the professions. Furthermore, we argue that continuing to ignore the veterinary profession, and animals more generally, in sociological research will result in an impoverished and partial understanding of contemporary healthcare and occupations.     

Development of Sexual Expectancies among Adolescents: Contributions by Parents,Peers and the Media

To expand the scant research on sexual expectancies development among non–sexually active adolescents, we examined the relationship between adolescents' exposure to four socializing agents—mother/female guardian, father/male guardian, peers, and television programs with high sexual content—and their endorsement of four sexual expectancies: social benefit, pleasure, social risk, and health risk. Data are from Waves 2 and 3 of a three-wave annual longitudinal study conducted among California adolescents, the majority of whom were not sexually active (N = 914, 84%). Structural equation models were conducted to examine cross-sectional and longitudinal associations between the socializing agents and the sexual expectancies. Cross-sectional results indicate associations between peer sexual communication and social benefit, pleasure, and social risk expectancies. A positive association was found between exposure to music videos and social benefit expectancies, and a negative association was found between exposure to music videos and health risk expectancies. Longitudinal results suggest that communication with peers positively predicted pleasure expectancies and negatively predicted social risk expectancies. No other socializing agents were associated with any sexual expectancies. An invariance test found that significant correlations were similar across the different age groups. Results suggest that efforts to support positive sexual decision making among non–sexually active adolescents should target peer sexual communication.     

Joseph Gusfield and Social Problems Theory

Joseph R. Gusfield was a key figure in the emergence of constructionist social problems theory. His approach was characterized by: his determination to identify the cultural, structural, and historical context of claims; attention to the choices among alternatives that shaped how problems were defined; and the rhetoric used by advocates. He highlighted the role of ownership–the ability to define the terms in which social problems are constructed. His work is also notable for its skepticism regarding social scientists’ theorizing.     

The Social Nature of Demeanor*

Goffman argues that individuals offer themselves to the group through well demeanored appearance for which they are granted deference. In this paper, I try to expand Goffman's insights by focusing directly on demeanor itself. From observations in Intensive Care Units, I find that demeanor is an achievement, a cooperative social accomplishment, and a form of deference. It is normatively a working ideal by which individuals gain acceptance as competent group members. A well de-meanored appearance makes interaction more pleasant; it permits others to antici pate that one will try to conform to interactional norms; it facilitates whatever task is at hand; it validates the deference that an individual grants; and it is itself a form of deference. It does not remain the responsibility of the individual, and we must therefore examine how groups constitute individuals. From the analysis, I derive explanations of the level of demeanor in a given setting, and propositions predicting the behavior of individuals within a setting.     

PARENTAL CHOICE OF SCHOOL CHARACTERISTICS: ESTIMATION USING STATE-WIDE DATA

This article attempts to proxy parental alienation from public schools across states in order to obtain measures of quality dispersion and of the educational characteristics to which families are most sensitive. The indicator of alienation is the choice of private schooling. Since the likelihood of such choice is known from published enrollment ratios, the task is to explain why they vary so widely across states. Of the newer hypotheses tested, that of teacher strike records is strongly significant and in the expected direction. Other novel findings concern the share of administration, teacher memberships of the National Education Association and the proportion of whites to nonwhites in the population.     

Survival estimation and the effects of dependency among animals

Survival models assume that fates of individuals are independent, yet the robustness of this assumption has been poorly quantified. We examine how empirically derived estimates of the variance of survival rates are affected by dependency in survival probability among individuals. We used Monte Carlo simulations to generate known amounts of dependency among pairs of individuals and analyzed these data with Kaplan-Meier and Cormack-Jolly-Seber models. Dependency significantly increased these empirical variances as compared to theoretically derived estimates of variance from the same populations. Using resighting data from 168 pairs of black brant ( Branta bernicla nigricans ), we used a resampling procedure and program RELEASE to estimate empirical and mean theoretical variances. We estimated that the relationship between paired individuals caused the empirical variance of the survival rate to be 155% larger than the empirical variance for unpaired individuals. Monte Carlo simulations and use of this resampling strategy can provide investigators with information on how robust their data are to this common assumption of independent survival probabilities.