1,721,080 research outputs found
Quantile regression for count data: jittering versus regression coefficients modelling in the analysis of credits earned by university students after remote teaching
Full text linkThe extension of quantile regression to count data raises several issues. We compare the traditional approach, based on transforming the count variable using jittering, with a recently proposed approach in which the coefficients of quantile regression are modelled by parametric functions. We exploit both methods to analyse university students’ data to evaluate the effect of emergency remote teaching due to COVID-19 on the number of credits earned by the students. The coefficients modelling approach performs a smoothing that is especially convenient in the tails of the distribution, preventing abrupt changes in the point estimates and increasing precision. Nonetheless, model selection is challenging because of the wide range of options and the limited availability of diagnostic tools. Thus the jittering approach remains fundamental to guide the choice of the parametric functions
Lernen die jüngeren Generationen von den älteren? Ideale Familiengröße in Europa: Trend zur Kleinfamilie erweist sich als längerfristig
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Growth models for the progress test in Italian dentistry degree programs
No full textIn 2017, for the first time in Italy, the students enrolled in Dental Schools performed a Progress test. The results allow us to analyse the evolution of students’ abilities during the course years. Furthermore, we can evaluate the coherence of the learning pattern with the core curriculum. We analyse the results of the Progress Test with a mixed-effects growth-curve binomial model for the number of correct answers, using fixed effects for the topics and random effects for the universities. The learning trajectories for each topic are modelled via polynomials of time. Using the Empirical Bayes predictions of random effects, we obtain the trajectories for the Italian universities, which show substantial heterogeneity in the starting levels and growth rates. The results give insights into inequalities in the educational process across Italian universities to be exploited for planning interventions
Does community-based rehabilitation enhance the multidimensional well-being of deprived persons with disabilities? A multilevel impact evaluation.
No full textThe aim of this paper is to explore the impact of community-based rehabilitation programs on the well-being of deprived persons with disabilities from a multidimensional perspective using a multilevel analysis. This approach explicitly takes into account potential bias due to the fact that persons with disabilities live and interact in different local contexts (villages). Data were obtained from a large-scale survey in two districts of Karnataka State (India). The impact of community-based rehabilitation on deprived persons with disabilities was positive and significant. Its magnitude varies across different dimensions of well-being
Mixed-effect models with trees
Full text linkTree-based regression models are a class of statistical models for predicting continuous response variables when the shape of the regression function is unknown. They naturally take into account both non-linearities and interactions. However, they struggle with linear and quasi-linear effects and assume iid data. This article proposes two new algorithms for jointly estimating an interpretable predictive mixed-effect model with two components: a linear part, capturing the main effects, and a non-parametric component consisting of three trees for capturing non-linearities and interactions among individual-level predictors, among cluster-level predictors or cross-level. The first proposed algorithm focuses on prediction. The second one is an extension which implements a post-selection inference strategy to provide valid inference. The performance of the two algorithms is validated via Monte Carlo studies. An application on INVALSI data illustrates the potentiality of the proposed approach
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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