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161.
    
Two new methods to estimate the asymptotic covariance matrix for marginal maximum likelihood estimation of cognitive diagnosis models (CDMs), the inverse of the observed information matrix and the sandwich-type estimator, are introduced. Unlike several previous covariance matrix estimators, the new methods take into account both the item and structural parameters. The relationships between the observed information matrix, the empirical cross-product information matrix, the sandwich-type covariance matrix and the two approaches proposed by de la Torre (2009, J. Educ. Behav. Stat., 34, 115) are discussed. Simulation results show that, for a correctly specified CDM and Q-matrix or with a slightly misspecified probability model, the observed information matrix and the sandwich-type covariance matrix exhibit good performance with respect to providing consistent standard errors of item parameter estimates. However, with substantial model misspecification only the sandwich-type covariance matrix exhibits robust performance.  相似文献   
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Mixture analysis of count data has become increasingly popular among researchers of substance use, behavioral analysis, and program evaluation. However, this increase in popularity seems to have occurred along with adoption of some conventions in model specification based on arbitrary heuristics that may impact the validity of results. Findings from a systematic review of recent drug and alcohol publications suggested count variables are often dichotomized or misspecified as continuous normal indicators in mixture analysis. Prior research suggests that misspecifying skewed distributions of continuous indicators in mixture analysis introduces bias, though the consequences of this practice when applied to count indicators has not been studied. The present work describes results from a simulation study examining bias in mixture recovery when count indicators are dichotomized (median split; presence vs. absence), ordinalized, or the distribution is misspecified (continuous normal; incorrect count distribution). All distributional misspecifications and methods of categorizing resulted in greater bias in parameter estimates and recovery of class membership relative to specifying the true distribution, though dichotomization appeared to improve class enumeration accuracy relative to all other specifications. Overall, results demonstrate the importance of accurately modeling count indicators in mixture analysis, as misspecification and categorizing data can distort study outcomes.  相似文献   
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Amongst a number of negative life sequelae associated with childhood adversity is the later expression of a higher dispositional tendency to experience anger and frustration to a wide range of situations (i.e., trait anger). We recently reported that an association between childhood adversity and trait anger is moderated by individual differences in both threat-related amygdala activity and executive control-related dorsolateral prefrontal cortex (dlPFC) activity, wherein individuals with relatively low amygdala and high dlPFC activity do not express higher trait anger even when having experienced childhood adversity. Here, we examine possible structural correlates of this functional dynamic using diffusion magnetic resonance imaging data from 647 young adult men and women volunteers. Specifically, we tested whether the degree of white matter microstructural integrity as indexed by fractional anisotropy modulated the association between childhood adversity and trait anger. Our analyses revealed that higher microstructural integrity of multiple pathways was associated with an attenuated link between childhood adversity and adult trait anger. Amongst these pathways was the uncinate fasciculus (UF; ΔR 2 = 0.01), which not only provides a major anatomical link between the amygdala and prefrontal cortex but also is associated with individual differences in regulating negative emotion through top-down cognitive reappraisal. These findings suggest that higher microstructural integrity of distributed white matter pathways including but not limited to the UF may represent an anatomical foundation serving to buffer against the expression of childhood adversity as later trait anger, which is itself associated with multiple negative health outcomes.  相似文献   
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This article investigates how test-takers change their strategies to handle increased test difficulty. An adult sample reported their test-taking strategies immediately after completing the tasks in a reading test. Data were analyzed using structural equation modeling specifying a measurement-invariant, ability-moderated, latent transition analysis in Mplus (Muthén & Asparouhov, 2011). It was found that almost half of the test-takers (47%) changed their strategies when encountering increased task-difficulty. The changes were characterized by augmenting comprehending-meaning strategies with score-maximizing and test-wiseness strategies. Moreover, test-takers' ability was the driving influence that facilitated and/or buffered the changes. The test outcomes, when reviewed in light of adjusted test-taking strategies, demonstrated a form of process-based validity evidence.  相似文献   
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Automated essay scoring engines (AESEs) are becoming increasingly popular as an efficient method for performance assessments in writing, including many language assessments that are used worldwide. Before they can be used operationally, AESEs must be “trained” using machine-learning techniques that incorporate human ratings. However, the quality of the human ratings used to train the AESEs is rarely examined. As a result, the impact of various rater effects (e.g., severity and centrality) on the quality of AESE-assigned scores is not known. In this study, we use data from a large-scale rater-mediated writing assessment to examine the impact of rater effects on the quality of AESE-assigned scores. Overall, the results suggest that if rater effects are present in the ratings used to train an AESE, the AESE scores may replicate these effects. Implications are discussed in terms of research and practice related to automated scoring.  相似文献   
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Media-multitasking involves simultaneous engagement with information streams from multiple media sources, and is most prevalent in young adults. Heavy media-multitasking has been associated with differential performance on tasks involving attentional control and working memory relative to light media-multitasking. The aim of the present study was to systematically investigate relationships between executive functions and self-reported media-multitasking. Healthy participants (N?=?112, aged 18–25, male N?=?36) completed a battery of 10 traditional executive function tasks, that included assessments of attentional inhibition, response inhibition, working memory, and cognitive flexibility. Scores on the individual executive function tasks were correlated against frequency of self-reported media-multitasking, but no significant relationships were found. Trait anxiety, however, was found to be significantly associated with greater frequency of self-reported media-multitasking. The present study found no evidence of a relationship between the frequency of self-reported media-multitasking and executive functioning. The possible reasons for this are discussed.  相似文献   
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