The effectiveness of weighted least squares means and variance adjusted based fit indices in assessing local dependence of the rasch model: Comparison with principal component analysis of residuals.

Local independence is a principal assumption of applying latent variable models. Violations of this assumption might be stemmed from dimensionality (trait dependence) and statistical independence of item responses (response dependence). The purpose of this study is to evaluate the sensitivity of weighted least squares means and variance adjusted (WLSMV) based global fit indices to violations of local independence in Rasch models, and compare those indices to principal component analysis of residuals (PCAR) that is widely used for Rasch models. Dichotomous Rasch model is considered in this simulation study. The results show that WLSMV-based fit indices could detect trait dependence, but are to be limited with regard to response dependence. Additionally, WLSMV-based fit indices have advantages over the use of PCAR since WLSMV-based global fit indices are consistent regardless of sample size and test length. Though it is not recommended to apply exact benchmarks for those indices, they would provide practitioners with a method for evaluating the degree to which assumption violation is problematic for their data diagnostic purpose.

Teacher and student race as a predictor for negative feedback during instruction.

There is a long and persistent gap between the academic achievement of White and Black students in America's schools. Further, Black students are suspended from school at a rate that is more than three times greater than White students. While there has been some suggestion that perhaps teacher-student racial matching may be part of a solution, the research does not currently provide adequate support for teacher race alone to be sufficiently effective. This study analyzed 41 Black and White teacher-student dyad mixes in elementary schools and another 41 in a high school to examine how teacher and student race interact in terms of teacher and student behaviors. While Black students were slightly more likely to be off-task and disruptive, both Black and White teachers were found to provide significantly more negative feedback to Black students regardless of their behavior. Implications for teacher practice and future study are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Application of the Korean Version of the Modified Barthel Index: Development of a keyform for use in Clinical Practice.

OBJECTIVE: To demonstrate the clinical application of the Korean version of the Modified Barthel Index (K-MBI) using Rasch analysis. METHODS: A total of 276 patients with neurological disorders were assessed with the K-MBI in outpatient clinics. The Rasch partial-credit model was used to generate a keyform based on investigating the psychometric properties of the K-MBI, including dimensionality, precision (person strata and reliability), and hierarchical item difficulty. The Minimal Detectable Change (MDC) in item difficulty was used to establish right-challenging treatment goals and long-term treatment plans. RESULTS: The findings demonstrated that the Korean version of the MBI satisfied the assumption of unidimensionality. It also showed a hierarchical structure in terms of item difficulty, good reliability (Cronbach alpha, 0.92), and approximately five distinct person strata (4.6). The MDC (raw score, 20.1) of the item difficulty of the test items demonstrated equivalent cutoff scores for targeted short-term treatment goals on the keyform, a Rasch-derived display of patient responses. Long-term treatment goals were identified based on the test items of the keyform. CONCLUSIONS: The findings suggest that a Rasch keyform can be applied to clinical practice in Korean settings by identifying clinically and statistically meaningful test items and their step thresholds as short- and long-term goals.