Robust designs for experiments with blocks

ABSTRACT

For experiments running in field plots or over time, the observations are often correlated due to spatial or serial correlation, which leads to correlated errors in a linear model analyzing the treatment means. Without knowing the exact correlation matrix of the errors, it is not possible to compute the generalized least-squares estimator for the treatment means and use it to construct optimal designs for the experiments. In this paper, we propose to use neighborhoods to model the covariance matrix of the errors, and apply a modified generalized least-squares estimator to construct robust designs for experiments with blocks. A minimax design criterion is investigated, and a simulated annealing algorithm is developed to find robust designs. We have derived several theoretical results, and representative examples are presented.     

Socialization in a Medium-Security Reformatory*

D'après des interviews auprès d'un échantillonnage d'environ trente détenus récemment liberés, cette étude approfondit à la fois les étapes de la socialisation des prisonniers aux normes et aux valeurs de la sous-culture des detenus ainsi que les principales variables qui influent sur la proportion et sur le degré de socialisation. Mention est faite du rôle des experiences antérieures à l'emprisonnement telles que la résidence au sein de quartiers de classes ouvrières ou inférieures, le comportement en bandes ("gang"), l'incarcération dans des institutions pénitentiaires de comté ou des institutions pour jeunes et les processus de sélection à l'interieur de la maison de correction; mais on a accordé une attention speciale aux pressions uniformisantes qui s'exercent au dortoir, ainsi qu'au groupe de travail et autres groupes primaires charactéristiques de cette institution; on a aussi mentioné les exigences rencontrées par les nouveaux prisonniers lors de leur adaptation.     

Creating more trauma-informed services for children using assessment-focused tools

This article promotes integrating assessment and evidence-based practice in the treatment of traumatized children through a review of two newly developed trauma assessment tools: (1) the Child Welfare Trauma Referral Tool (CWT), and (2) Assessment-Based Treatment for Traumatized Children: A Trauma Assessment Pathway Model (TAP). These tools use pathways and algorithms to increase understanding of individual child trauma victims, and assist professionals working with children to make appropriate referral and treatment decisions within both child welfare and mental health contexts.     

Race, racial resentment, attentiveness to the news media, and public opinion toward the Jena Six

Objective. We outline the role of race, racial resentment, and attentiveness to news in structuring public opinion toward the prosecution of the Jena Six, the name given to six African-American high school students who beat a white student, five of whom were subsequently charged with attempted second-degree murder.Method. We rely on a telephone survey of 428 registered voters collected in the aftermath of the protests in Jena, Louisiana.Results. Public reactions were heavily filtered by race and associated with measures of racial resentment. African Americans followed news about the protests more closely, believed race was the most important consideration in the decision to prosecute, and believed the decision to prosecute was the wrong decision. Racially conservative white respondents were less likely to believe race was the most important consideration in the decision to prosecute and were more likely to believe that the decision to prosecute was the right decision. Consistent with theories of agenda setting and framing, attentiveness to the news influenced perceptions regarding the importance of race in the decision to prosecute but not whether the decision was the right decision.Conclusions. At least within the context of the Deep South, race and racial attitudes continue to be an important predictor of public reactions to racially charged events. Attentiveness to the news influenced the lens through which events were interpreted, but not perceptions of whether the outcome was the right decision.     

Choosing a school: parental decision-making when special schools are an option

Parental rights to choose a school are widely acknowledged. School choices for parents of children with disability have been discussed in the academic literature; however, the decision-making process itself is largely hidden. It is vital to understand parental decision-making around school choice more deeply, given the high regard with which this is viewed. Six focus groups were held in Queensland, Australia in 2013 to explore parental decision-making. Data were collected from 30 parents with children of different ages, some of whom were eligible for special school enrolment. Most parents felt constrained in choosing a school yet eager to make decisions themselves. Most described the process as rational. Findings suggest that when special school was an option, decision-making felt more restricted and complex. Factors such as difficulty accessing reliable information and pressure from professionals added to the complexity. It was concluded that final school selection did not reliably reflect parental preferences.     

Human Rights and the Social Work Curriculum: Integrating Human Rights into Skill-Based Education Regarding Policy Practice Behaviors

This article provides a model for social work educators seeking to integrate human rights content in the policy course. Each of the four policy-related practice behaviors (e.g., policy formulation, policy analysis, policy advocacy, and collaboration in policy practice) is examined with respect to the traditional methods used in social welfare policy courses and the ways in which these methods can be expanded to include human rights content. Available literature and multimedia resources are noted and practical human rights applications are presented with the goal of supporting efforts to achieve this integration.     

Wealth Mobility of Families Raising Children in the Twenty-First Century

Wealth inequality between the top and bottom deciles has grown over the last 20 years (Piketty and Zucman in Wealth and inheritance in the long run, Centre for Economic Policy Research, London, 2014), as has the racial wealth gap (Shapiro et al. in The roots of the widening racial wealth gap: explaining the black–white economic divide. Institute on Assets and Social Policy, Brandeis University, Waltham, 2013. http://iasp.brandeis.edu/pdfs/Author/shapiro-thomas-m/racialwealthgapbrief.pdf). Within these broad trends of inequality, some families are able to get ahead and grow their wealth, while others are not. Yet we do not understand well the critical variables that increase the likelihood of wealth mobility across the life course—within the same generation. This paper addresses this gap and investigates the following questions: What accounts for intra-generational relative and absolute wealth mobility for families with children in the first decade of the twenty-first century? And how does it differ by race? The paper draws on two longitudinal data sets—the Panel Study of Income Dynamics household survey data matched with neighborhood-level US Census data (1999–2011), and the IASP Leveraging Mobility (LM) study (1998–2011). Applying an integrated mixed methods design, analyses are conducted in three stages: (1) A grounded theory analytic approach of the LM data determines key variables of wealth mobility: homeownership, income, employment characteristics, extended family wealth, negative life events, and neighborhood factors; (2) regression analyses test these indicators for absolute and relative wealth mobility; and (3) recontextualization through further analyses of LM data deepen the regression results by illustrating the pathways of significant wealth mobility predictors. Results reveal that increasing family income, larger family transfers, consistent long-term homeownership, and in some cases white-collar occupations increase the likelihood of upward relative wealth mobility. Negative life events, higher rates of neighborhood poverty, and black race are negatively correlated with the amount of wealth growth. These key drivers of wealth mobility highlight the need for targeted policies that reinforce and expand opportunities for all families to build wealth over the life course.     

A Mixed-Methods Approach to Refining and Measuring the Construct of Positive Risk-Taking in Adolescence

Adolescence is a peak period for risk-taking, but research has largely overlooked positive manifestations of adolescent risk-taking due to ambiguity regarding operationalization and measurement of positive risk-taking. We address this limitation using a mixed-methods approach. We elicited free responses from contemporary college students (N = 74, M_age = 20.1 years) describing a time they took a risk. Qualitative analysis informed the construction of a self-report positive risk-taking scale, which was administered to a population-based sample of adolescents (N = 1,249, M_age = 16 years) for quantitative validation and examination of associations with normative and impulsive personality. Sensation seeking predicted negative and positive risk-taking, whereas extraversion and openness were predominantly related to positive risk-taking. Results provide promising evidence for a valid measure of adolescents' engagement in positive risks.