A Comparison of Multilevel Imputation Schemes for Random Coefficient Models: Fully Conditional Specification and Joint Model Imputation with Random Covariance Matrices

Abstract

Literature addressing missing data handling for random coefficient models is particularly scant, and the few studies to date have focused on the fully conditional specification framework and “reverse random coefficient” imputation. Although it has not received much attention in the literature, a joint modeling strategy that uses random within-cluster covariance matrices to preserve cluster-specific associations is a promising alternative for random coefficient analyses. This study is apparently the first to directly compare these procedures. Analytic results suggest that both imputation procedures can introduce bias-inducing incompatibilities with a random coefficient analysis model. Problems with fully conditional specification result from an incorrect distributional assumption, whereas joint imputation uses an underparameterized model that assumes uncorrelated intercepts and slopes. Monte Carlo simulations suggest that biases from these issues are tolerable if the missing data rate is 10% or lower and the sample is composed of at least 30 clusters with 15 observations per group. Furthermore, fully conditional specification tends to be superior with intraclass correlations that are typical of crosssectional data (e.g., ICC?=?.10), whereas the joint model is preferable with high values typical of longitudinal designs (e.g., ICC?=?.50).     

语言的群体间偏差研究

个体在用语言来描述他人的行为时,会因为描述对象的群体种类不同而有偏差,具体表现为在描述群体内成员的积极行为和群体外成员的负向行为时,会使用较高抽象水平的词;在描述群体外成员的积极行为和群体内成员的负向行为时,会使用较低抽象水平的词。这种抽象水平的差异由语言范畴模型来具体表明。Maass等人把这种描述上的偏差命名为语言的群体间偏差。并认为在这一现象下有两种机制：动机机制和认知机制,研究表明认知机制能解释大部分语言的群体间偏差现象,而动机机制会在群体内形象受到威胁时发挥作用。     

中国传统文化取向管理人员的成败归因风格研究

选用台湾杨国枢先生编制的《传统性量表》和自编《管理成败归因风格问卷》,随机选取542名企业管理人员,调查研究中国传统文化取向管理人员的成败归因风格特征。研究发现：1）“孝亲敬祖”和“宿命自保”文化取向的人,成功外归因的倾向显著地高于成功内归因倾向。2）“男性优越”、“权威守成”、“宿命自保”文化取向的人,失败不可控外归因倾向显著地高于失败内归因倾向。     

无决策成分的靶记忆与源记忆的加工深度比较

本研究通过两个实验来比较源记忆和靶记忆的难度。实验一比较两种记忆提取阶段的事件相关电位（ERPs）。实验二设置较高的成功标准,比较两者达标所需的时间,以此比较它们的难度。在实验一中,被试先进行项目记忆任务,接着进行源记忆任务（从两位虚拟人处接收项目,并记住项目的来源）和靶记忆任务（向两位虚拟人递送项目,并记住项目的去向）。源记忆和靶记忆的测试阶段要求被试再认项目的源或靶,并记录提取阶段的脑电。结果显示,虽然源记忆与靶记忆的正确率没有显著差异,但是在正确提取的ERP中观察到,两者与回想有关的LPC之间有边缘显著差异（靶记忆比源记忆更趋正向,且在顶区差异最明显）,这说明在回想上,靶记忆可能比源记忆需要更深的加工。实验二将源记忆和靶记忆结合在同一个任务中,要求被试反复尝试,直至两种记忆的正确率都达到较高的成功标准（近90%）。结果进一步证实,源记忆的加工水平深于源记忆。     

Depressive Symptoms among Children with ODD: Contributions of Parent and Child Risk Factors in a Chinese Sample

Oppositional Defiant Disorder (ODD) is a developmental disorder characterized by serious and persistent social impairment, especially stressful interactions with parents. Although previous studies demonstrated associations between parent mental health and children’s ODD symptoms, less attention has been paid to integrating both parent and child risk factors. The purpose of the current study was to investigate the associations among parent emotion regulation, child emotion regulation, parental depression, and child depression in Chinese children with ODD. A total of 234 children with ODD ranging in age from 6 to 13 years, along with their fathers or mothers, completed questionnaires. Results indicated that: (1) Parent emotion regulation, parental depression and child emotion regulation were significantly correlated with children’s depressive symptoms. (2) Parent emotion regulation was related to children’s depression indirectly through parental depression and child emotion regulation. (3) Child emotion regulation fully mediated the relationship between parent emotion regulation and child depression, and also fully mediated the relationship between parental and child depression. These findings highlight the need to improve parent emotion regulation and pay attention to parental mental health, because both risk factors may exacerbate their children’s emotion regulation difficulties and further associate the high level of depressive symptoms among children with ODD.     

Masked translation priming effects with low proficient bilinguals

Non-cognate masked translation priming lexical decision studies with unbalanced bilinguals suggest that masked translation priming effects are asymmetric as a function of the translation direction (significant effects only in the dominant [L1] to nondominant [L2] language translation direction). However, in contrast to the predictions of most current accounts of masked translation priming effects, bidirectional effects have recently been reported with a group of low proficient bilinguals Duyck & Warlop 2009 (Experimental Psychology 56:173–179). In a series of masked translation priming lexical decision experiments we examined whether the same pattern of effects would emerge with late and low proficient Greek (L1)–Spanish (L2) bilinguals. Contrary to the results obtained by Duyck and Warlop, and in line with the results found in most studies in the masked priming literature, significant translation priming effects emerged only when the bilinguals performed the task with L1 primes and L2 targets. The existence of the masked translation priming asymmetry with low proficient bilinguals suggests that cross-linguistic automatic lexico-semantic links may be established very early in the process of L2 acquisition. These findings could help to define models of bilingualism that consider L2 proficiency level to be a determining factor.     

The appeal of vague financial forecasts

Prior findings suggest managers often choose ranges to communicate uncertainty in future earnings. We analyzed earnings forecasts over 11 years and find higher earnings uncertainty firms are more likely to choose range estimates. We study investors’ attitudes to forecast precision and argue investors’ evaluations of forecasts can be explained by a sequential non-compensatory two-stage process – First, investors determine whether a point or a range estimate is more appropriate for a particular domain based on the congruence principle. Then, they seek the most precise reasonable range to maximize informativeness. Results from three experiments indicate the preference for (im)precision is non-monotonic – it peaks for low levels of imprecision and diminishes when the range gets wider, and is consistent with participants’ desire for congruent and informative estimates, and supports the claim that investors favor forecasts that are as precise as warranted by the information available, but not more precise.     

Beyond rhyme or reason: ERPs reveal task-specific activation of orthography on spoken language

Metaphonological tasks, such as rhyme judgment, have been the primary tool for the investigation of the effects of orthographic knowledge on spoken language. However, it has been recently argued that the orthography effect in rhyme judgment does not reflect the automatic activation of orthographic codes but rather stems from sophisticated response strategies. Such a claim stands in sharp contrast with recent findings using event-related brain potentials (ERPs) in lexical and semantic tasks, which were taken to suggest that orthographic information occurs early enough to affect the core process of lexical access. Here, we show that the electrophysiological signature of the orthography effect in rhyme judgment is indeed different from the one obtained in online lexical or semantic tasks. That is, we did not find the orthography effect in the 300-350 ms time window which has previously been shown to process lexical information in the lexico-semantic tasks, but the effect appeared within the 175-250 ms and the 375-750 ms time-windows which we interpreted to reflect segmentation and decisional process, respectively. We conclude that the interactions between phonology and orthography are task-specific. Metaphonological tasks appear of limited use for studying the core processes and interactions that underlie lexical access.     

经皮冠状动脉介入治疗(PCI)后无复流现象的综合解析

现已证明无复流现象的发生会明显降低经皮冠状动脉介入治疗(PCI)效果,影响患者近、远期预后.应用综合思维探讨无复流现象发生的机理、制定预防策略至关重要.     

可拓逻辑研究展望

可拓学是由我国学者自主创立的一门新学科,它研究以形式化的模型分析事物拓展的可能性和开拓创新的规律,形成解决矛盾问题的方法。中国科学院权威杂志《科学通报》在评论文章中指出:“可拓学是一门充满生命力的新学科,它的创立是中国人的骄傲,它不仅属于中国,更属于世界。”[1]经过30年的不断开拓,可拓学已经发展成为一门横跨哲学、数学与工程学的交叉学科,我们哲学界也可以积极对相关问题进行科学的研究和探索。本文拟从逻辑的角度谈谈可拓逻辑的研究设想,以期能够引起哲学界、逻辑学界对可拓学研究的关注。一可拓逻辑的研究价值人类的历史…