Sensitivity analysis and choosing between alternative polytomous IRT models using Bayesian model comparison criteria

Polytomous Item Response Theory (IRT) models are used by specialists to score assessments and questionnaires that have items with multiple response categories. In this article, we study the performance of five model comparison criteria for comparing fit of the graded response and generalized partial credit models using the same dataset when the choice between the two is unclear. Simulation study is conducted to analyze the sensitivity of priors and compare the performance of the criteria using the No-U-Turn Sampler algorithm, under a Bayesian approach. The results were used to select a model for an application in mental health data.     

Coherent Hypothesis Testing

Multiple hypothesis testing, an important quantitative tool to report the results of scientific inquiries, frequently leads to contradictory conclusions. For instance, in an analysis of variance (ANOVA) setting, the same dataset can lead one to reject the equality of two means, say μ₁ = μ₂, but at the same time to not reject the hypothesis that μ₁ = μ₂ = 0. These two conclusions violate the coherence principle introduced by Gabriel in 1969 Gabriel, K. R. (1969), “Simultaneous Test Procedures - Some Theory of Multiple Comparisons,” The Annals of Mathematical Statistics, 40, 224–250. Available at http://www.jstor.org/stable/2239213[Crossref] , [Google Scholar], and lead to results that are difficult to communicate, and, many times, embarrassing for practitioners of statistical methods. Although this situation is common in the daily life of statisticians, it is usually not discussed in courses of statistics. In this work, we enrich the teaching and discussion of this important topic by investigating through a few examples whether several standard test procedures are coherent or not. We also discuss the relationship between coherent tests and measures of support. Finally, we show how a Bayesian decision-theoretical framework can be used to build coherent tests. These approaches to coherence enlighten when such property is appealing in multiple testing and provide means of obtaining it.     

Ichthyofauna diet changes in response to urbanization: the case of upper Paranapanema River basin (Brazil)

Alterations in stream environments can alter fish food availability, but there is little research data related to the impacts of urbanization on fish diets in tropical streams. Thus, we sought to compare the diet of ten fish species in urbanized and non-urbanized streams reaches. Fish stomach contents were obtained for four urban and five non-urban stream reaches from two medium-sized cities. We verified the similarity of diet composition from urbanized/non-urbanized streams. In-stream features mainly related to the substrate highlighted a perturbation gradient: gravel, pebbles and cobbles were associated to the wider urban reaches while silt were representative in the narrow pools from non-urban streams. Fishes changed their diet in response to urban and non-urban treatments. Omnivorous fishes consumed more detritus and Chironomidae and less terrestrial adult insects in urban reaches, while invertivorous fish consumed more terrestrial adult insects and Trichoptera larvae in the non-urbanized stream reaches. Although the management of the physical structure of streams in Brazil has been basically focused on riparian reforestation, our results suggest that a restoration plan for urban streams cannot be limited to reforestation of its surroundings, but also need to consider the physical structure of the channel, especially the substrate, which contributes to promote in-stream variability.     

Les écarts salariaux dans une profession à prédominance féminine: le travail domestique informel et flexible au Portugal

Les auteures étudient les effets des arrangements informels et flexibles sur les salaires des travailleurs domestiques employés par des personnes privées au Portugal. Les estimations indiquent que l'emploi formel est bénéfque aux travailleurs, que leur contrat soit stable ou fexible. Toutefois, les mécanismes du marché du travail et des fonctionnements sociaux favorisent la persistance des inégalités, surtout au détriment des travailleurs migrants. Les qualifcations ne sont ni valorisées ni rétribuées, et on observe des salaires supérieurs chez les travailleurs occasionnels et ceux qui ont plusieurs employeurs ou s'occupent de personnes âgées. Cependant, ces travailleurs restent exposés à l'exploitation et à l'insécurité.     

新生代农民工制度化政治参与的对策思考

新生代农民工是我国公民政治参与的重要组成部分。但是当前我国新生代农民工的政治参与主要表现为非制度化参与,存在着制度化参与的困境。为破解这一困境,需要采取提高收入、完善相关制度建设,加强和普及对新生代农民工的教育和培训,提高他们的社会认同感等措施,促使新生代农民工的政治参与活动由非制度化向制度化转变。     

Sustainability Ranking for Cuban Tourist Destinations Based on Composite Indexes

This investigation approaches the levels and the predictors of loneliness among migrant youths from returned migrant families from France to Portugal. Three research questions guided the study: (1) Does loneliness of migrant youths differ from those who have never migrated? (2) Are migrant youths’ re-acculturation factors related to their loneliness? (3) Is the adaptation of migrant youths linked to their loneliness? The answer to these questions is important to improve migrant youths’ re-acculturation experiences and their adaptation. The sample included 222 youths from returned migrant families from France. Participants completed the brief Portuguese version of the Revised UCLA Loneliness Scale (ULS-6), in addition to measures of re-acculturation and adaptation. A control group comprised of 211 Portuguese adolescents who have never migrated was also involved in the investigation. Youths from returned migrant families showed lower levels of loneliness than their native Portuguese counterparts who have never migrated. Demographic, re-acculturation, and adaptation factors were significantly related to adolescents’ loneliness. Major predictors of loneliness were age at return, contacts with peers without migratory experience, perceived discrimination, stressful adaptation experience, and satisfaction with life.     

Ergonomic evaluation of the preparation of cuttings and minicuttings for eucalyptus seedling production, with the use of scissors

This study was conducted in a nursery for eucalyptus seedling production in a forest Company, located in the southern state of Bahia, Brazil. It aimed to evaluate the ergonomic conditions of the preparation of cuttings and mini-cuttings with scissors for Eucalyptus seedling production to increase well-being, satisfaction and safety and minimizing the occurrence of occupational diseases, also improving the process efficiency and final product quality. Environmental conditions, levels of noise, postures, RSI risk and physical workload were assessed. The environmental conditions complied with the recommended norms, except at certain times of day, when workers should make compensation breaks. The workers that collect minicuttings presented postures classified as normal by OWAS. On the other hand, the posture of workers dealing with cutting preparation requires corrections in a short run. The workers were subjected to moderate RSI risk due to the high degree of repeatability found. The physical workload was classified as mild, with no need for ergonomic interventions.     

Inclusive design in the implementation of projects for schools modernization in Portugal - case studies

The Project for Schools Modernization taking place in Portugal, with an estimated total investment of 2450 million for the intervention in the first 205 schools, provide the reclassification of 332 secondary schools by 2015. One of the questions we can pose is if the authorities and the teams of architects selected to design these schools considered fundamental for the correctness of architectural barriers within the school and its accessibility the implementation of standards and principles of inclusion of children/teenagers with special needs within their school environment. As most of the projects are already being implemented, the main aim of this paper is to present the outcomes of a comparative analysis and synthesis of six schools located in the northern part of the country. This analysis occurs from the of Participatory Design perspective which appeals to the experience of the disable children to look (or evaluate) the negative and positive factors in terms of physical space, interpreted by inclusive design rules and orientations. Therefore, the evaluation of schools modernization project, and its discussion, is central for the understanding how these children are addressed in projects which are directed at them.