PERFORMANCE OF A LOCALIZED TREE SPLITTING CRITERION IN TREE AVERAGING

This paper explores the performance of the local splitting criterion devised by Bremner & Taplin for classification and regression trees when multiple trees are averaged to improve performance. The criterion is compared with the deviance used by Clark & Pregibon's method, which is a global splitting criterion typically used to grow trees. The paper considers multiple trees generated by randomly selecting splits with probability proportional to the likelihood for the split, and by bagging where bootstrap samples from the data are used to grow trees. The superiority of the localized splitting criterion often persists when multiple trees are grown and averaged for six datasets. Tree averaging is known to be advantageous when the trees being averaged produce different predictions, and this can be achieved by choosing splits where the splitting criterion is locally optimal. The paper shows that use of locally optimal splits gives promising results in conjunction with both local and global splitting criteria, and with and without random selection of splits. The paper also extends the local splitting criterion to accommodate categorical predictors.     

Multistate modeling of clinical hold in randomized clinical trials

A clinical hold order by the Food and Drug Administration (FDA) to the sponsor of a clinical trial is a measure to delay a proposed or to suspend an ongoing clinical investigation. The phase III clinical trial START serves as motivating data example to explore implications and potential statistical approaches for a trial continuing after a clinical hold is lifted. In spite of a modified intention‐to‐treat (ITT) analysis introduced to account for the clinical hold by excluding patients potentially affected most by the clinical hold, results of the trial did not show a significant improvement of overall survival duration, and the question remains whether the negative result was an effect of the clinical hold. In this paper, we propose a multistate model incorporating the clinical hold as well as disease progression as intermediate events to investigate the impact of the clinical hold on the treatment effect. Moreover, we consider a simple counterfactual censoring approach as alternative strategy to the modified ITT analysis to deal with a clinical hold. Using a realistic simulation study informed by the START data and with a design based on our multistate model, we show that the modified ITT analysis used in the START trial was reasonable. However, the censoring approach will be shown to have some benefits in terms of power and flexibility.     

Dispositional Affect and Career Barriers: The Moderating Roles of Gender and Coping

This study examined whether gender and coping efficacy for career barriers moderated the relationship between both positive and negative dispositional affect and perceptions of career barriers. The sample included 294 undergraduate students (195 women, 99 men) from a large, midwestern university. Gender and coping efficacy did not moderate the relationship between negative dispositional affect and perceptions of career barriers. Coping efficacy for career barriers did moderate the relationship between positive dispositional affect and perceptions of career barriers for both women and men in different directions. When investigating women separately, the results revealed a weakening of the negative beta weight between positive affect and perception of career barriers as coping scores increased. An opposite effect was found for men; there was a reduction of the positive beta weight between positive affect and perception of career barriers as coping scores increased. Interventions to address perceptions of career barriers based on gender and dispositional affect are discussed.     

Reports of Conferences,Institutes, and Seminars

This quarter's column features a report from the Association of College & Research Libraries (ACRL) Conference, held March 25–28, 2015, in Portland, OR; a couple of reports from the Ohio Valley Group of Technical Services Librarians (OVGTSL) Conference, held May 18–20 in Terre Haute, IN; one report from NASIG, held May 27–30 in Washington, DC; and several reports from the American Library Association (ALA) Annual Conference, held June 25–30 in San Francisco, CA. Topics discussed range from scholarly publishing, copyright and authors’ rights—including as they relate to zines—privacy and analytics, and linked data.     

Marital Sorting and Parental Wealth

The extent of marital sorting by socioeconomic background has implications for the intergenerational transmission of inequality, the role of marriage as a mechanism for social mobility, and the extent of cross-group interactions within a society. However, studies of assortative mating have disproportionately focused on spouses’ education, rather than their social origins. Using data from the Panel Study of Income Dynamics (PSID), and exploiting the unique genealogical design of the data set, we study the degree to which spouses sort on the basis of parental wealth. We find that the estimated correlation in parental wealth among married spouses, after controlling for race and age, is about .4. Importantly, we show that controlling for spousal education explains only one-quarter of sorting based on parental wealth. We show that our results are robust to accounting for measurement error in spousal reports of parental wealth and for selection into and out of marriage.     

School Connectedness Buffers the Effects of Negative Family Relations and Poor Effortful Control on Early Adolescent Conduct Problems

This study examined the unique and interactive contributions of school connectedness, negative family relations, and effortful control to subsequent early adolescent conduct problems. Data were collected from 476 adolescents when they were initially in the 6th and 7th grades and again 1 year later. Results from hierarchical regression analyses showed that even after controlling for negative family relations, effortful control, baseline levels of conduct problems, and gender, school connectedness contributed to decreasing subsequent conduct problems. Examination of 2- and 3-way interactions indicated that high levels of school connectedness offset the adverse effects of negative family relations for boys and girls and the adverse effects of low levels of effortful control for girls. Findings underscore the role of school connectedness as a protective factor for early adolescent conduct problems.     

Kreative als aktivierte Wirtschaftsbürger. Zur wohlfahrtsstaatlichen Rahmung von künstlerisch-kreativer Arbeit

This text lights up the welfare-state framing of artistic-creative work in the German Welfare regime. The argument is that the welfare state framing of the cultural and creative industries has substantially changed as well normatively as with regard to welfare instruments. With this, it is part of the change of the German Welfare regime which, based upon the Agenda 2010-policy change, has turned from a caring to an activating Welfare regime. While in the 1960s and the 1970s artists have been perceived as a socially vulnerable group who need to be protected from market risks, nowadays this social group is mainly regarded as entrepreneurs. In a nutshell, the new welfare-state arrangement with regard to artistic-creative work addresses the “deficit” entrepreneur. It consists of three core aspects. First, there is a semantic reconstruction of the empiric field. It is modeled as ‘Kultur- und Kreativwirtschaft’ and, therefore, it is mainly perceived as an economically productive field. Second, to fulfill the productive hopes and aims, artists and creatives are perceived to be activated sociopolitically and to be disciplined economically in order to change them into economically valuable entrepreneurs. Third, the new welfare arrangement is partly privatised and aims to create market oriented competitiveness among artists and creatives. The text is based upon empiric investigations in the cultural economy and creative economy which the author carries out since 2007.