Joint coverage probability in a simulation study on continuous-time Markov chain parameter estimation

Parameter dependency within data sets in simulation studies is common, especially in models such as continuous-time Markov chains (CTMCs). Additionally, the literature lacks a comprehensive examination of estimation performance for the likelihood-based general multi-state CTMC. Among studies attempting to assess the estimation, none have accounted for dependency among parameter estimates. The purpose of this research is twofold: (1) to develop a multivariate approach for assessing accuracy and precision for simulation studies (2) to add to the literature a comprehensive examination of the estimation of a general 3-state CTMC model. Simulation studies are conducted to analyze longitudinal data with a trinomial outcome using a CTMC with and without covariates. Measures of performance including bias, component-wise coverage probabilities, and joint coverage probabilities are calculated. An application is presented using Alzheimer's disease caregiver stress levels. Comparisons of joint and component-wise parameter estimates yield conflicting inferential results in simulations from models with and without covariates. In conclusion, caution should be taken when conducting simulation studies aiming to assess performance and choice of inference should properly reflect the purpose of the simulation.     

The language ideologies of multilingual nannies in London

In the globalized economy, multilingualism is increasingly perceived as a way of maximizing competitiveness, even in the family home. In the United Kingdom, multilingualism has become an asset for nannies, granting privileged access to a niche job market. Adopting the theoretical lens of language ideology, we identify sites and forms of language evaluation within the nannies’ discursive construction of their language work. Using thematic analysis of interview and focus group data with nannies, we examine how nannies represent their English and L1 language practices, verbalizations, and embodiments. Findings suggest that, rather than language practices, it is the verbalization of the symbolic value of multilingualism (normally through the medium of English) that grants nannies an advantageous position in the market. This market is made possible by upper-middle-class families, whose privileging of specific languages and speakers perpetuates eliteness, gendered language work, and problematic approaches to second language learning.     

Evaluating the psychometrics of the SSIS SEL in a socio-economically diverse sample

The increasing interest in implementing social-emotional learning (SEL) interventions within schools calls for more reliable and valid assessment tools to measure the effectiveness of SEL programs. We investigated the factor structure and psychometric properties of the Social Skills Improvement System – Social-Emotional Learning Edition (SSIS SEL) with a group of ethnically and socio-economically diverse grade 3 students in Ontario, Canada (n = 427). The SSIS SEL is an age-normed measure used for the evaluation of interventions and prevention initiatives. Data collected included both teacher-report and student self-report measures. The factor structure proposed by the scale developers was not replicated using this smaller single grade sample. However, the study demonstrates evidence of good construct and convergent validity supporting the novel factor structure. Results from this study suggest that more research on the SSIS SEL's application in real-world intervention research programs is needed.