A review of R-packages for random-intercept probit regression in small clusters

Generalized Linear Mixed Models (GLMMs) are widely used to model clustered categorical outcomes. To tackle the intractable integration over the random effects distributions, several approximation approaches have been developed for likelihood-based inference. As these seldom yield satisfactory results when analyzing binary outcomes from small clusters, estimation within the Structural Equation Modeling (SEM) framework is proposed as an alternative. We compare the performance of R-packages for random-intercept probit regression relying on: the Laplace approximation, adaptive Gaussian quadrature (AGQ), Penalized Quasi-Likelihood (PQL), an MCMC-implementation, and integrated nested Laplace approximation within the GLMM-framework, and a robust diagonally weighted least squares estimation within the SEM-framework. In terms of bias for the fixed and random effect estimators, SEM usually performs best for cluster size two, while AGQ prevails in terms of precision (mainly because of SEM's robust standard errors). As the cluster size increases, however, AGQ becomes the best choice for both bias and precision

A new approach for within-subject mediation analysis in AB/BA crossover designs

Crossover trials are widely used in psychological and medical research to assess the effect of reversible exposures. In such designs, each subject is randomly allocated to a sequence of conditions, enabling the evaluation of treatment differences within each individual. When there are but two possible exposures -each assessed during one of two time periods-, the crossover study is referred to as an AB/BA design. The goal of this presentation is to discuss mediation analysis in such simple crossover studies. We do so by considering within-subject mediation from a counterfactual-based perspective and by deriving expressions for the direct and indirect effects. Employing simulation studies, the performance of several existing methods will be assessed and compared to that of a novel one we propose. We show that the new method yields unbiased and efficient estimators for the direct and indirect effect, under a minimalistic set of `no unmeasured confounding'-assumptions. Finally, we illustrate the different techniques with data from a neurobehavioral study

Taking Part: a Twentieth-Century Life

In 1920, thinking he would find a job as a writer, Robert Josephy met with a new publisher, Alfred Knopf--and ended up as an office boy for eight dollars a week. After a few intense years he was promoted to production manager and learned to design books, an occupation he traded on for the better part of thirty years. He designed the nascent Viking Press first six books, worked for Simon and Sdiuster and Random House in their early years, became a freelancer in high demand, and served as president of and teacher at the Book and Magazine Guild both before and after it became a full-fledged union. Many of his books are now collectors\u27 items. This is just one of the ways Josephy has been taking part in what has turned out to be an unusually full and intriguing life. Involvement and imagination have fueled the life and times of this book designer/farmer/political activist/environmentalist. Born in 1903 to a prosperous Long Island family, Josephy is still very much a self-made man. His acquaintances and experiences span a range that includes some of this century\u27s brightest stars and most controversial issues—Alexander Calder, Lewis Mumford, Alfred Stieglitz, H. L. Mencken, Malcolm Cowley. He had to resign from the Bethel Democratic Town Committee for supporting Henry Wallace over Harry Truman. Called the oldest living liberal Democrat in Connecticut, Josephy was twice persuaded to run as the heavily outnumbered Democratic candidate for the Connecticut state legislature—forty-two years apart. Exercising his design skills in a different field, he planted one of Connecticut\u27s largest fruit farms, the Blue Jay Orchards in Bethel. He has served on the Connecticut Board of Agriculture, was a longtime board member of the Connecticut Agricultural Experiment Station, and has been a driving force in the farmland preservation movement. Fast-paced, multifaceted, opinionated, sometimes outrageous, and always interesting, Josephy and his life reflect the variety and breadth of changing experiences the United States has offered during the twentieth century. His vivid memoir serves to remind us that ordinary people lead singular lives: they have true stories worth the telling, stories that are often more than compelling—if not stranger—than fiction.https://ir.uiowa.edu/uipress_sl/1019/thumbnail.jp

Preschool predictors of mathematics in first grade children with autism spectrum disorder

AbstractUp till now, research evidence on the mathematical abilities of children with autism spectrum disorder (ASD) has been scarce and provided mixed results. The current study examined the predictive value of five early numerical competencies for four domains of mathematics in first grade. Thirty-three high-functioning children with ASD were followed up from preschool to first grade and compared with 54 typically developing children, as well as with normed samples in first grade. Five early numerical competencies were tested in preschool (5–6 years): verbal subitizing, counting, magnitude comparison, estimation, and arithmetic operations. Four domains of mathematics were used as outcome variables in first grade (6–7 years): procedural calculation, number fact retrieval, word/language problems, and time-related competences. Children with ASD showed similar early numerical competencies at preschool age as typically developing children. Moreover, they scored average on number fact retrieval and time-related competences and higher on procedural calculation and word/language problems compared to the normed population in first grade. When predicting first grade mathematics performance in children with ASD, both verbal subitizing and counting seemed to be important to evaluate at preschool age. Verbal subitizing had a higher predictive value in children with ASD than in typically developing children. Whereas verbal subitizing was predictive for procedural calculation, number fact retrieval, and word/language problems, counting was predictive for procedural calculation and, to a lesser extent, number fact retrieval. Implications and directions for future research are discussed

A view to a grill: Designing park infrastructure for Uusimaa parks

Deep relationships between people and the natural environment can be fostered in the smallest of interventions. This master’s thesis of Collaborative and Industrial Design explores the research, design, and construction of small infrastructure for a Finnish provincial park association. UUVI (short for Uudenmaan Virkistysalueyhdistys) is a government-funded organization with 37 nature reserves ranging in size from 1.1 to 450 hectares. In many of these parks infrastructure is deteriorating, and new day use shelters, fire sites, woodsheds, and signposts are needed. Grilling, hiking, foraging, and fishing are beloved summertime activities in Finnish culture and are cemented in law through the every-man’s rights enjoyed in the country. The Finnish relation-ship with nature is a deep and cultural one. This thesis explores how built park infrastructure can foster the cultural connection with nature in Finnish parks. Theoretical underpinnings of the nature-culture relationship are explored. Once seen in a dualistic manner, nature was seen to be a place absent of people. Since then, the understanding of nature in academic discourse has changed, and contemporary views of nature place humans within and part of it. Place can be defined as the space in which humans and landscape interact: where landscapes leave an impression on people and people leave an impression on the land. The benefits of nature experiences are well documented, and can be intentional or not. Ways in which park infrastructure can encourage and deepen nature experiences are explored. In this project, five different park elements are designed, each with varying amounts of input from the different stakeholders involved. A wood stove specifically designed for grilling was conceptualized by UUVI Field Manager Mikael Avellan, and re-dimensioned and drawn for this thesis. A large woodshed was also co-designed with Avellan and includes a sliding roof for easier refilling. Signpost, bench, and shelter designs were influenced heavily by user research conducted in Kopparnäs-Störsvik park, as well as continued input from UUVI staff with their considerable experi-ence. Research insights encouraged drawing the attention outwards from the shelters to promote incidental nature experiences; the use of more numerous but smaller shelters to disperse crowds; employing premium materials for longevity and to discourage vandalism; and the importance of accessibility. Detailed dimensioned drawings were created for each project element, and are now in the process of being prototyped and constructed by various manufacturers

A quantum-like model for complementarity of preferences and beliefs in dilemma games

We propose a formal model to explain the mutual influence between observed behavior and subjects' elicited beliefs in an experimental sequential prisoner's dilemma. Three channels of interaction can be identified in the data set and we argue that two of these effects have a non-classical nature as shown, for example, by a violation of the sure thing principle. Our model explains the three effects by assuming preferences and beliefs in the game to be complementary. We employ non-orthogonal subspaces of beliefs in line with the literature on positive-operator valued measure. Statistical fit of the model reveals successful predictions

Centering lower-level interactions in multilevel models

In hierarchical designs, the effect of a lower level predictor on an outcome may oftentimes be confounded by an (un)measured upper level variable. When such confounding is left unaddressed, the effect of the lower level predictor will be estimated with bias. As to remove any such bias in a linear random intercept model, researchers often separate the lower level effect into a within- and between-component (under a specific set of confounding-assumptions). When the effect of the lower level predictor is additionally moderated by another lower level predictor, an interaction between both predictors needs to be included into the model. To again address any possible unmeasured upper level confounding, this interaction term also requires partitioning into a within- and between- cluster component. This can be achieved by first multiplying both predictors and to consequently centering that product term, or vice versa. We demonstrate that the former centering approach proves much more efficient and robust against misspecification of cross- and upper-level effects, compared to the latter