Optimal correction for continuity in the chi-squared test in 2×2 tables

The most common asymptotic procedure for analyzing a 2 × 2 table (under the conditioning principle) is the ‰ chi-squared test with correction for continuity (c.f.c). According to the way this is applied, up to the present four methods have been obtained: one for one-tailed tests (Yates') and three for two-tailed tests (those of Mantel, Conover and Haber). In this paper two further methods are defined (one for each case), the 6 resulting methods are grouped in families, their individual behaviour studied and the optimal is selected. The conclusions are established on the assumption that the method studied is applied indiscriminately (without being subjected to validity conditions), and taking a basis of 400,000 tables (with the values of sample size n between 20 and 300 and exact P-values between 1% and 10%) and a criterion of evaluation based on the percentage of times in which the approximate P-value differs from the exact (Fisher's exact test) by an excessive amount. The optimal c.f.c. depends on n, on E (the minimum quantity expected) and on the error α to be used, but the rule of selection is not complicated and the new methods proposed are frequently selected. In the paper we also study what occurs when E ≥ 5, as well as whether the chi-squared by factor (n-1).     

L'insécurité de l'emploi et ses conséquences pour les salariés: l'effet modérateur de la dépendance envers l'emploi

La mondialisation et l'intensification de la concurrence internationale ont provoqué l'apparition de formes d'emploi flexibles et une précarisation de l'emploi. Le sentiment d'insécurité chez les salariés produit des effets sur leurs attitudes et leurs intentions que les auteurs se proposent d'examiner. Après un tour d'horizon des travaux de recherche sur la théorie du stress et la relation existant entre insécurité de l'emploi et ses conséquences, ils testent, sur un échantillon de 942 salariés d'Espagne, deux hypothèses. La première est que l'insécurité de l'emploi présente, d'une part, une corrélation négative avec la satisfaction au travail et l'engagement envers l'organisation et, d'autre part, une corrélation positive avec l'intention de quitter l'organisation; et la seconde, qu'il existe une interaction entre l'insécurité de l'emploi, le besoin économique et l'employabilité qui influe sur la prédiction de ces résultats.     

汉方美容,最IN的自我养护大淘宝

安全回归最热门的汉方美容 肌肤泡在化学的海洋里颤颤危危,保不准还赔上健康本钱.只养不伤的汉方成分纯粹自然,许多国际上呼风唤雨的大牌都已经挪为己用,我们为什么不把自家宝贝回归到手上来?     

A multivariate uniformity test for the case of unknown support

A test for the hypothesis of uniformity on a support S⊂ℝ ^d is proposed. It is based on the use of multivariate spacings as those studied in Janson (Ann. Probab. 15:274–280, 1987). As a novel aspect, this test can be adapted to the case that the support S is unknown, provided that it fulfils the shape condition of λ-convexity. The consistency properties of this test are analyzed and its performance is checked through a small simulation study. The numerical problems involved in the practical calculation of the maximal spacing (which is required to obtain the test statistic) are also discussed in some detail.     

“Having a family is the new normal”: Parenting in neoliberal academia during the COVID-19 pandemic

The outbreak of the COVID-19 pandemic has made explicit the burden of care shouldered by academic mothers, in addition to juggling their scholarly commitments. Although discussions are abundant on the impact of caring responsibilities on the careers of women academics, neoliberal academia continues to minimize such struggles. Despite the disruptions to family routines caused by the health crisis, academic institutions have expected academic mothers and fathers to continue undertaking their professional responsibilities at the same level as before, disregarding their parenting demands. This paper contributes to the research on parenthood in academia by looking at how, throughout the pandemic, academic parents have negotiated the tensions between parenthood and academic demands, and by investigating the strategies they use to confront neoliberal culture of academic performativity, even amid the health crisis. The paper engages with the “space invaders” concept used by Puwar (2004) to analyze the “hypervisibility” of academic mothers' and fathers' “bodies out of place” during the pandemic, and to investigate their “renegade acts” against the uncaring attitudes of their institutions. Evidence is drawn from a qualitative study conducted during December 2020 and January 2021 among scholars affiliated to Portuguese academic institutions: 17 in-depth interviews conducted with women, and two mixed-gender focus groups. Our results research reveal how the experiences of academic mothers and fathers were not uniform during the pandemic. In addition, it shows how, despite their commitment to their academic responsibilities, these parents have crafted various resistance strategies to confront the institutional pressure to continue maintain their working routines, and instead positioning themselves as “more than just academics.”     

Special issue: Child protection in the digital age. Latent profiles in cyberbullying and the relationship with self-concept and achievement goals in preadolescence

In recent years, the scientific community has taken an interest in cyberbullying research due to the emotional and educational impact on all those involved. However, the scant evidence on samples from primary education is derived from statistical methodologies focusing on the individual, which generate specific profiles rather than acting roles. The present study focuses on the profiles of cyberbullying and its variability with the levels of self-concept and academic goals, using a sample of 548 Spanish primary education students aged 10–13 (M = 10.95, SD = 0.7). After analysing the data using Latent Class Analysis and MANOVA, the profiles developed were ‘not-involved’ (38.82%), ‘moderate victimization’ (37.17%), ‘high bully-victimization’ (19.29%) and ‘low victimization’ (4.7%). In addition, the group of students with the not-involved profile scored higher on the self-concept of their relationship with their parents, in language, in mathematics and their general self-concept than the group with moderate victimization. The same pattern was also observed for learning goals. The findings have significant implications for the creation of person-centred cyberbullying prevention programmes that permit a more targeted approach to cyberbullying behaviours in order to halt its progress.