Approximability of Dodgson’s rule

It is known that Dodgson’s rule is computationally very demanding. Tideman (Soc Choice Welf 4:185–206, 1987) suggested an approximation to it but did not investigate how often his approximation selects the Dodgson winner. We show that under the Impartial Culture assumption the probability that the Tideman winner is the Dodgson winner converges to 1 as the number of voters increase. However we show that this convergence is not exponentially fast. We suggest another approximation—we call it Dodgson Quick—for which this convergence is exponentially fast. Also we show that the Simpson and Dodgson rules are asymptotically different.     

Developing Responsive Preventative Practices: Key Messages from Children's and Families’ Experiences of the Children's Fund

As part of the prevention and social inclusion agenda, the Children's Fund, set up in 2000, has developed preventative services for children at risk of social exclusion. Drawing on a large qualitative dataset of interviews conducted in 2004/05 with children, young people and their parents/carers who accessed Children Fund services, this article analyses key practices and approaches valued by children and parents. These included: specialist support tailored to individual support needs, family‐oriented approaches, trusting relationships with service providers, multi‐agency approaches and sustainability of services. Finally, the article draws out key lessons for the future development of preventative services.     

Social Protection in Vietnam and Obstacles to Progressivity

The present paper analyzes the incidence and progressivity of Vietnamese state income transfers using survey data from the Vietnamese Household Living Standards Survey 2004. Data quality and sample selection issues are highlighted, especially in the coverage of rural-urban migrants. Simple income-based profiles of incidence are matched to several influences that confound and complicate the measurement of progressivity. The issue of the informal economy is highlighted through analysis of both the extent of private inter-household transfers and remittances and their relationship with state transfers, and in the informal charges that accompany uptake of state services and other petty corruption. Second, the issue of user-charges for health and education services is considered, as a considerable portion of state transfers are related to the take up of schooling and health care. Third, the issue of behavioral effects is also considered, concentrating on private inter-household transfers. The paper concludes by drawing together the evidence and the obstacles to measurement and progressivity to argue a range of data collection, methodological and policy recommendations.     

Conditional approval: discussion points from the PSI conditional approval expert group

The European Agency for the Evaluation of Medicinal Products has recently completed the consultation of a draft guidance on how to implement conditional approval. This route of application is available for orphan drugs, emergency situations and serious debilitating or life-threatening diseases. Although there has been limited experience in implementing conditional approval to date, PSI (Statisticians in the Pharmaceutical Industry) sponsored a meeting of pharmaceutical statisticians with an interest in the area to discuss potential issues. This article outlines the issues raised and resulting discussions, based on the group's interpretation of the legislation. Conditional approval seems to fit well with the accepted regulatory strategy in HIV. In oncology, conditional approval may be most likely when (a) compelling phase II data are available using accepted clinical outcomes (e.g. progression/recurrence-free survival or overall survival) and Phase III has been planned or started, or (b) when data are available using a surrogate endpoint for clinical outcome (e.g. response rate or biochemical measures) from a single-arm study in rare tumours with high response, compared with historical data. The use of interim analyses in Phase III for supporting conditional approval raises some challenging issues regarding dissemination of information, maintenance of blinding, potential introduction of bias, ethics, switching, etc.     

Formative evaluation of a motivational intervention for increasing physical activity in underserved youth

The present study was designed to develop an innovative motivational intervention (based on Self-Determination Theory and Social Cognitive Theory) to increase physical activity (PA) in underserved adolescents. Sixty-four adolescents (35 females, 29 males; 50% minority; 65% on reduced lunch program; ages 11-13 yr) participated in either an 8-week motivational intervention after-school (n = 32) or a typical after-school program (n = 32). The conceptual framework for the intervention targeted the social environment (perceived autonomy, perceived social support, participation, fun), cognitive mediators (perceived choice, self-efficacy, and relatedness/belongingness), and motivational orientation (intrinsic motivation, commitment, positive self-concept). Formative evaluation data was collected by staff through daily forms throughout the 8-week program and through observational data completed by independent objective observers during 2 weeks of the program. The major themes that were identified addressed theoretical concepts regarding the intervention and logistical issues in delivering the intervention. The data revealed information regarding the importance of the cognitive appropriateness of the PA and motivational activities, the environmental climate for promoting nurturing relationships, developing specific strategies for increasing intrinsic rather than extrinsic reinforcement, and developing methods for preventing social "cliques" and gender conflicts to maintain an appropriate level of support in the social climate. Themes for training staff included focusing on team building, leadership, and nurturing. This formative evaluation is being used to formalize a randomized trial to test the effects of a student-centered motivational intervention on increasing PA in underserved 6th graders.     

Missing data: Discussion points from the PSI missing data expert group

The Points to Consider Document on Missing Data was adopted by the Committee of Health and Medicinal Products (CHMP) in December 2001. In September 2007 the CHMP issued a recommendation to review the document, with particular emphasis on summarizing and critically appraising the pattern of drop‐outs, explaining the role and limitations of the ‘last observation carried forward’ method and describing the CHMP's cautionary stance on the use of mixed models. In preparation for the release of the updated guidance document, statisticians in the Pharmaceutical Industry held a one‐day expert group meeting in September 2008. Topics that were debated included minimizing the extent of missing data and understanding the missing data mechanism, defining the principles for handling missing data and understanding the assumptions underlying different analysis methods. A clear message from the meeting was that at present, biostatisticians tend only to react to missing data. Limited pro‐active planning is undertaken when designing clinical trials. Missing data mechanisms for a trial need to be considered during the planning phase and the impact on the objectives assessed. Another area for improvement is in the understanding of the pattern of missing data observed during a trial and thus the missing data mechanism via the plotting of data; for example, use of Kaplan–Meier curves looking at time to withdrawal. Copyright © 2009 John Wiley & Sons, Ltd.     

Disparities in Educational Opportunities and Outcomes: What Do We Know and What Can We Do?

This article examines disparities based upon poverty and race/ethnicity. After framing the issues by looking at national, state, and local data, it illustrates ways that social scientists can be involved in shaping educational practices and policies, focusing on the types of skills that are useful and on ways of thinking about the types of collaboration that are needed. Skills discussed are methodological as well as substantive; both types draw from existing knowledge bases. For collaboration, the model described is that of action research. Approaches are illustrated through personal examples drawn from collaborations with urban public schools. They include defining expected growth for students at different achievement levels, school accountability issues, and setting up long-term collaboration .     

Multi-Organizational Fields and Social Movement Organization Frame Content: The Religious Fro-Choice Movement*

As an explanatory method in studies of social movements, analyses of collective action frames have generally focused on the variable efficacy of the frames of social movement organizations (SMOs)in the mobilization of potential participants. However, this work has for practical reasons used the acknowledged analytic simplification that SMOs only target potential participants–and not opponents, elite decision makers, or the media–when constructing their frames. To incorporate multiple targets into future studies of SMO frame construction, this paper expands on the idea of a multi-organizational field. I propose that the characteristics of the targets in the field and the social structural and cognitive boundaries between them determine SMO frames. This perspective is demonstrated by analyzing changes in the collective action frames of SMOs in the religious pro-choice movement from 1967 to 1992. I argue that this perspective may explain findings where a frame fails to “resonate” with potential participants–the frame may not have been created with them in mind.