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631.
Exploratory factor analysis is a popular statistical technique used in communication research. Although exploratory factor analysis (EFA) and principal components analysis (PCA) are different techniques, PCA is often employed incorrectly to reveal latent constructs (i.e., factors) of observed variables, which is the purpose of EFA. PCA is more appropriate for reducing measured variables into a smaller set of variables (i.e., components) by keeping as much variance as possible out of the total variance in the measured variables. Furthermore, the popular use of varimax rotation raises some concerns about the relationships among the factors that researchers claim to discover. This paper discusses the distinct purposes of PCA and EFA, using two data sets as examples to highlight the differences in results between these procedures, and also reviews the use of each technique in three major communication journals: Communication Monographs, Human Communication Research, and Communication Research. 相似文献
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我国实行改革开放以来,经济发展取得了举世瞩目的成就,但随着开放步伐的加大,宗教渗透也越演越烈。在构建社会主义和谐社会的今天,和谐 相似文献
635.
Metastable-state alloy powders are usually synthesised by milling and occur as products of mechanical alloying (MA), but they are rarely used as starting materials for other MA processes. In this work, metastable-state alloy powders, including supersaturated solid-solution Cr(Mo)s and amorphous Cr(Mo)a were prepared in advance. Then, the Cr(Mo)s/Cr(Mo)a powder mixture was mechanically alloyed with elemental Cu to form Cu–Mo–Cr alloy. The effects of the metastable-state powder Cr(Mo)s/Cr(Mo)a on MA of the immiscible Cu–Mo–Cr system were evaluated. Phases and microstructures of the milled powders were analysed by XRD and TEM, respectively. The results show that amorphous Cu-60wt.%Cr(Mo) and supersaturated solid-solution Cu-20wt.%Cr(Mo) alloy powders can be synthesised by MA. It is concluded that MA of the Cu–Mo–Cr ternary alloy system is significantly promoted when elemental Cu powder is milled with metastable-state alloy powder Cr(Mo)s/Cr(Mo)a. Furthermore, the promoting effect of amorphous Cr(Mo)a on MA the Cu–Mo–Cr alloy system is much greater than that of supersaturated solid-solution Cr(Mo)s, during the milling process. 相似文献
636.
The focus of cognitive diagnosis (CD) is on evaluating an examinee’s strengths and weaknesses in terms of cognitive skills learned and skills that need study. Current methods for fitting CD models (CDMs) work well for large-scale assessments, where the data of hundreds or thousands of examinees are available. However, the development of CD-based assessment tools that can be used in small-scale test settings, say, for monitoring the instruction and learning process at the classroom level has not kept up with the rapid pace at which research and development proceeded for large-scale assessments. The main reason is that the sample sizes of the small-scale test settings are simply too small to guarantee the reliable estimation of item parameters and examinees’ proficiency class membership. In this article, a general nonparametric classification (GNPC) method that allows for assigning examinees to the correct proficiency classes with a high rate when sample sizes are at the classroom level is proposed as an extension of the nonparametric classification (NPC) method (Chiu and Douglas in J Classif 30:225–250, 2013). The proposed method remedies the shortcomings of the NPC method and can accommodate any CDM. The theoretical justification and the empirical studies are presented based on the saturated general CDMs, supporting the legitimacy of using the GNPC method with any CDM. The results from the simulation studies and real data analysis show that the GNPC method outperforms the general CDMs when samples are small. 相似文献
637.
Judgments about future memory performance (metamemory judgments) are known to be susceptible to illusions and bias. Here we asked whether metamemory judgments are affected, like many other forms of judgment, by numerical anchors. Experiment 1 confirmed previous research showing an effect of informative anchors (e.g., past peer performance) on metamemory monitoring. In four further experiments, we then explored the effects of uninformative anchors. All of the experiments obtained significant anchoring effects on metamemory monitoring; in contrast, the anchors had no effect on recall itself. We also explored the anchoring effect on metamemory control (restudy choices) in Experiment 4. The results suggested that anchors can affect metamemory monitoring, which in turn affects metamemory control. The present research reveals that informative and, more importantly, uninformative numbers that have no influence on recall itself can bias metamemory judgments. On the basis of the current theoretical understanding of the anchoring effect and metamemory monitoring, these results offer insight into the processes that trigger metacognitive biases. 相似文献
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Yan Liu Leishi Fei Xiaomin Sun Cong Wei Fang Luo Zhongquan Li Liming Shen Gang Xue Xiuyun Lin 《Journal of child and family studies》2018,27(5):1415-1427
Research on the antecedents and underlying mechanisms of the formation of adolescent social trust is scant. Family and school are two major environments in which adolescents become socialized. The current study examined the effect of parental rearing behaviors (rejection, emotional warmth and overprotection) on adolescent social trust, exploring the mediating role of adolescent self-esteem and the multilevel moderated role of the Level 2 variable class justice climate. The sample included 612 (12–16 years old) middle school students in China. Participants completed the s-EMBU, the Rosenberg Self-esteem Scale, Rosenberg’s Faith in People Scale and the perceptions of class justice scale, along with other control variables. The results suggested that parental rearing behaviors significantly predicted adolescent social trust, regardless of adolescent gender or age. Additional mediation analysis suggested that parental rearing behaviors had both direct effects on adolescent social trust and indirect effects through adolescent self-esteem. Further multilevel structural equation modeling indicated that class justice climate moderated the effect of parental rejection on adolescent self-esteem. The findings suggest that family and school practice jointly shape adolescents’ social trust. How parents treat their children has a huge influence on the degree to which their children trust other people. In addition, perceived class justice could buffer the harmfulness of negative parental rearing behaviors. 相似文献
640.
Yaoyao Sun Shumei Wang Ming Qi Menglian Wu Dan Zhang Yang Yang 《Psychology, health & medicine》2018,23(7):797-803
This study aimed to examine the psychological status among Chronic Atrophic Gastritis (CAG) patients and to find the cumulative effects of risk and protective factors. A sample of 101 CAG patients completed the investigation. Hierarchical linear regression was used to find risk and protective factors, and examine the cumulative effects in risk factor index (RFI) and protective factor index (PFI). Results showed that nine symptoms from SCL-90-R were severer among CAG patients than those in adult norm. Risk factors including positive family history of cancer and higher negative life events could predict higher GSI (β = 0.206, p = 0.023; β = 0.398, p < 0.001; R² = 0.203); more household resistant, positive coping and stronger resilience were protective factors and could predict GSI negatively (β = -0.188, p = 0.020; β = -0.350, p = 0.012; β = ?0.066, p = 0.621; R² = 0.190). The GSI was positively correlated with RFI (β = 0.338, p < 0.001; R² = 0.113) and negatively related to PFI (β = ?0.378, p < 0.001; R² = 0.133). In conclusion, CAG patients suffered from various psychological distress, and the protective factors should be enhanced cumulatively to protect against psychological distress. 相似文献