Split Hamiltonian Monte Carlo

We show how the Hamiltonian Monte Carlo algorithm can sometimes be speeded up by “splitting” the Hamiltonian in a way that allows much of the movement around the state space to be done at low computational cost. One context where this is possible is when the log density of the distribution of interest (the potential energy function) can be written as the log of a Gaussian density, which is a quadratic function, plus a slowly-varying function. Hamiltonian dynamics for quadratic energy functions can be analytically solved. With the splitting technique, only the slowly-varying part of the energy needs to be handled numerically, and this can be done with a larger stepsize (and hence fewer steps) than would be necessary with a direct simulation of the dynamics. Another context where splitting helps is when the most important terms of the potential energy function and its gradient can be evaluated quickly, with only a slowly-varying part requiring costly computations. With splitting, the quick portion can be handled with a small stepsize, while the costly portion uses a larger stepsize. We show that both of these splitting approaches can reduce the computational cost of sampling from the posterior distribution for a logistic regression model, using either a Gaussian approximation centered on the posterior mode, or a Hamiltonian split into a term that depends on only a small number of critical cases, and another term that involves the larger number of cases whose influence on the posterior distribution is small.     

Leadership of highly creative people in highly creative fields: A historiometric study of scientific leaders

In recent years there has been a marked increase in the study of the influence of leadership on creativity, and the effects of this relationship on organizational performance. While a number of explanations have been broached with regard to the positive effects of leadership on creativity, many of these studies propose different, and often contradictory, methods for leaders to achieve these positive effects on creativity within their organizations and work groups. Additionally, little work has been done examining the effects of leadership on highly creative people in fields requiring creativity. The purpose of this study is to examine two existing leadership theories with regard to their viability as models to explain creative performance of eminent scientists. Eminent scientists represent a population of leaders of highly creative individuals in a field that values the production of innovative ideas and products as a marker of performance. Ninety-three excerpts from the biographies of scientists were content coded for leader behaviors and performance criteria. The results of this analysis indicate that a model based on strategic planning and product championing may serve to explain the positive effects of leadership on creativity in a highly creative population.     

Beyond ‘developmentalism’: A relational and embodied approach to young children's development

This article begins by discussing ‘developmentalism’, one of the key debates that has characterised the current theoretical impasse in the development of childhood studies. I use Norbert Elias's concept of the relation between love and learning as a foundation to develop the way in which young children's development is a non-linear, temporal and embodied process. I argue that we need to develop a relational approach that moves beyond some of the binary divisions between ‘nature’ and ‘biology’, drawing on concepts from particular theoretical traditions that have been under-utilised, particularly the relational school of psychoanalysis and the work of Maurice Merleau-Ponty.     

Parent–Adolescent Sexual Communication and Its Association With Adolescent Sexual Behaviors: A Nationally Representative Analysis in the Netherlands

Sexual communication is a principal means of transmitting sexual values, beliefs, expectations, and knowledge from parents to children. Although this area has received considerable research attention, more studies with representative samples are needed to assure that findings are reflective of populations of interest. A nationally representative sample of parent–adolescent dyads (N = 2,965; mean adolescent age = 13.8 years) in the Netherlands was employed to examine the frequency of parent–adolescent sexual communication and its association with adolescent sexual behaviors (defined as sexual initiation, condom use, and contraceptive pill use). Nine communication topics in the areas of anatomy, relationships and rights, and protection and contraception were examined. In all, 75%of parents reported having discussed at least one topic multiple times with their adolescents. Romantic relationships were discussed most frequently. Hierarchical logistic regression analyses indicated that parent–adolescent sexual communication on protection and contraception was positively associated with adolescent sexual initiation and contraceptive pill use but not condom use. This may reflect that adolescents, when they become sexually active, are more likely to discuss sexuality with their parents. Findings are interpreted within the context of Dutch culture, which is generally accepting of adolescent sexuality and characterized by open sexual communication.     

The Read Feed: Reviews

Abstract

Michelle DeMars reviews Academic Libraries for Commuter Students: Research-Based Strategies. Hayley Moreno reviews Coding with XML for Efficiencies in Cataloging and Metadata: Practical Applications of XSD, XSLT, and XQuery.     

Was Cicourel’s critique in Methods and Measurement in Sociology too radical?

This article is a contribution to a mini symposium on the 50th anniversary of the publication of A V Cicourel’s Method and Measurement in Sociology (1964). The central theme of the book is reviewed – the problem of the relationship between everyday language and cultural meanings, and the language of measurement in social research – and the lack of an adequate ontology of social actors is identified as being the cause of the problem. The solution offered by Alfred Schütz – that social scientific language should be derived from everyday language – is discussed and it is argued that this was probably too radical at the time the book was published, and is still generally neglected in the social sciences.     

Sociology and the European Court of Human Rights

This article offers a sociological analysis of the jurisprudence of the European Court of Human Rights (ECtHR). Adopting a sociological jurisprudence approach, the article aims to demonstrate the unique and valuable contribution that sociology can make to understanding key aspects of international human rights law. Whilst the article seeks to develop an agenda for critical sociological research on human rights law, it also aims to persuade those charged with the supervision of human rights of the value of sociological analysis. To achieve this, the article focuses on three separate but inter‐related aspects of ECtHR jurisprudence: first, it considers the ECtHR's approach to consensus in its adjudication of human rights complaints; second, it examines the social control implications of the ECtHR's decisions and judgments; and third, it assesses how conceptualizations of social identity are often foundational to the ECtHR's reasoning.     

James - stein regression estimation in a prediction context

Two types of shrunken estimators of regression coefficients are studied in the context of stochastic predictor variables. Emphasis is placed on the choice of the shrinkage parameters, using a ‘deleted-observation’ concept which is motivated by predictive ability.     

Measuring Sharedness of Team-Related Knowledge: Design and Validation of a Shared Mental Model Instrument

Many researchers have explored how people share and construct similar mental models in teams. They have claimed that successful team performance depends on a shared mental model of team members about task, team, equipment and situation. Most of the literature has illustrated simplified relationships between a team's mental model and their performance without a valid instrument addressing the confined and relevant constructs of a shared mental model. This paper describes the instrument development steps and the conceptual framework for factors associated with shared mental models. After development and refinement, the instrument was finalized for use to measure team-related knowledge. The final instrument consists of 42 items that are linked to the five emergent factors of shared mental models including general task and team knowledge, general task and communication skills, attitude toward teammates and task, team dynamics and interactions, and team resources and working environment.