Reversible jump methods for generalised linear models and generalised linear mixed models

A reversible jump algorithm for Bayesian model determination among generalised linear models, under relatively diffuse prior distributions for the model parameters, is proposed. Orthogonal projections of the current linear predictor are used so that knowledge from the current model parameters is used to make effective proposals. This idea is generalised to moves of a reversible jump algorithm for model determination among generalised linear mixed models. Therefore, this algorithm exploits the full flexibility available in the reversible jump method. The algorithm is demonstrated via two examples and compared to existing methods.     

Positive Changes in Perceptions and Selections of Healthful Foods by College Students After a Short-Term Point-of-Selection Intervention at a Dining Hall

Abstract

Objective: Determine the effects of a short-term, multi-faceted, point-of-selection intervention on college students’ perceptions and selection of 10 targeted healthful foods in a university dining hall and changes in their self-reported overall eating behaviors. Participants: 104 college students, (age 18–23) completed pre-I and post-I surveys. Methods: Pre-survey collected at dining hall in April 2007, followed by 3-week intervention then post-survey collected via email. Healthy choice indicators, large signs, table tents, flyers and colorful photographs with “benefit-based messages” promoted targeted foods. Response rate to both surveys was 38%. Results: Significantly more participants reported that healthful choices were clearly identified in the dining hall after the intervention. Over 20% of participants reported becoming more aware of healthful food choices in the dining hall after the intervention. Significant increases in self-reported intake were reported for cottage cheese and low-fat salad dressing, with a trend toward increased consumption of fresh fruit. Seven of the 14 assessed eating behaviors had significant changes in the desired direction. Increased awareness of healthful foods was the top reason for self-reported changes in overall eating behaviors. Conclusion: Short-term, multi-faceted, point-of-selection marketing of healthful foods in university dining halls may be beneficial for improving college students’ perceptions and selections of targeted healthful foods in the dining hall and may improve overall eating behaviors of college students.     

A window on the wider world? Rural children's use of information and communication technologies

The possibilities which information and communication technologies (ICT) offer people (or groups) to overcome the friction of distance and the constraints of materiality mean that these technologies are seen to have particular relevance in rural areas which have been historically characterised in terms of their economic and social perpheriality. In this paper, we draw on empirical research with children and their teachers and parents, to explore the opportunities which ICT are seen to offer young people living in rural areas. First, we examine the information that children access on-line and how young people make sense of this expanded terrain. Second we focus on communication, by considering children's use of email and chat rooms. Third, we explore how this information and these modes of communication may be shaping young people's sense of place in the world. Our findings expose a clear contrast between the ambitious and future orientated ways in which adults imagine ICT will expand their children's educational and employment opportunities, and social and spatial horizons, and the everyday ways in which these technologies actually emerge for children in practice.     

Integrating process and structure in the concept of youth: a case for secondary analysis

During its eighty-year history, the sociology of youth has provided a succession of partial explanations of the circumstances and responses of the young. The paper critically reviews this history and defines the challenge currently faced by sociologists: to develop a conceptual framework for understanding both the transitions young people pass through as they become adult, and the differential experiences of young people from different social groups. It is argued that such a framework requires the integration of the concepts of process and structure Secondary analysis of existing large data sets is suggested as an available means of meeting the challenge, since such data sets can provide both large representative samples which allow inter-group comparisons, and wide-ranging longitudinal data which allows the study of processes     

Resolving conflicts: principles and practice

Physicians and other medical professionals undergo extensive professional training for the privilege of obtaining their professional licenses. For most physicians, clinical training is conducted in extremely competitive circumstances. Many physicians endorse competition as an appropriate method for producing greater individual and collective competence within the profession. Competition, however, is a very limited way to resolve conflicts. And, in the current environment of greater resource restrictions and reform, the competitive model, at best, seems short-sighted. Many of the current relationships involving physicians and others are transitional, involving various partners in numerous practice and professional relationships. For example, medical practices are merging; hospitals are engaging physicians in numerous business structures, even employment. However, longer term relationships are enhanced by mutual respect and collaboration, rather than chronic competition to "win" one's rights over another. Thus, the need among physicians to enhance their conflict resolution skills is expanded in today's environment.     

On the estimation of multidimensional demographic models with population registration data

In this paper the estimation of multidimensional demographic models is investigated in situations where population registration data are available. With this kind of aggregate data, estimation by traditional methods is not possible. We look at two versions of the multidimensional model: the constant intensities model and the linear integration model. Some logical inconsistencies in the derivation of the latter are discussed. In particular, we argue that the linear integration model is not compatible with a Markov process. A new algorithm for the estimation of the constant intensities model with population registration data is proposed. Some preliminary results on the mathematical and statistical properties of this method are given. The algorithm is applied to Dutch nuptiality data.     

Causality in Contemporary American Sociology: An Empirical Assessment and Critique

Using a unique data set of causal usage drawn from research articles published between 2006–2008 in the American Journal of Sociology and American Sociological Review, this article offers an empirical assessment of causality in American sociology. Testing various aspects of what we consider the conventional wisdom on causality in the discipline, we find that (1) “variablistic” or “covering law” models are not the dominant way of making causal claims, (2) research methods affect but do not determine causal usage, and (3) the use of explicit causal language and the concept of “mechanisms” to make causal claims is limited. Instead, we find that metaphors and metaphoric reasoning are fundamental for causal claims‐making in the discipline. On this basis, we define three dominant causal types used in sociology today, which we label the Probabilistic, Initiating and Conditioning types. We theorize this outcome as demonstrating the primary role that cognitive models play in providing inference‐rich metaphors that allow sociologists to map causal relationships on to empirical processes.