Growth Mixture Models Outperform Simpler Clustering Algorithms When Detecting Longitudinal Heterogeneity,Even With Small Sample Sizes     

Daniel P. Martin  Timo von Oertzen 《Structural equation modeling》2013,20(2):264-275

The expansion in the number of people entering higher education has resulted in a substantial increase in the proportion of students enrolling in nontraditional modes, such as part-time study. This study examined the question of whether part-time study curtails the development of the types of intellectual capabilities needed for a knowledge-based economy, because the students would have markedly less exposure to a stimulating campus environment than their full-time counterparts. Graduates from discrete full- and part-time programs from 1 university in Hong Kong completed a survey seeking perceptions of the nurturing of a range of capabilities, together with measures of teacher-student relationships and type of teaching experienced. Two hypotheses were tested by structural equation modeling: (a) the same mechanism for capability development operated for full- and part-time modes and (b) the principal element of the mechanism was the nature of teaching and the quality of teacher-student interaction. Hypothesis 1 was supported because configural invariance between hypothesized models for capability development between the 2 modes was found. Hypothesis 2 was also supported because the models showed that the principal influence on capability development came from teaching for understanding, through promoting active learning experiences and the degree and quality of teacher-student interaction.  相似文献   

Accuracy of Estimates and Statistical Power for Testing Meditation in Latent Growth Curve Modeling     

JeeWon Cheong 《Structural equation modeling》2013,20(2):195-211

The latent growth curve modeling (LGCM) approach has been increasingly utilized to investigate longitudinal mediation. However, little is known about the accuracy of the estimates and statistical power when mediation is evaluated in the LGCM framework. A simulation study was conducted to address these issues under various conditions including sample size, effect size of mediated effect, number of measurement occasions, and R ₂ of measured variables. In general, the results showed that relatively large samples were needed to accurately estimate the mediated effects and to have adequate statistical power, when testing mediation in the LGCM framework. Guidelines for designing studies to examine longitudinal mediation and ways to improve the accuracy of the estimates and statistical power were discussed.  相似文献   

An Evaluation of Latent Growth Models for Propensity Score Matched Groups     

Walter L. Leite  Robert Sandbach  Rong Jin  Jann W. MacInnes  M. Grace-Anne Jackman 《Structural equation modeling》2013,20(3):437-456

Because random assignment is not possible in observational studies, estimates of treatment effects might be biased due to selection on observable and unobservable variables. To strengthen causal inference in longitudinal observational studies of multiple treatments, we present 4 latent growth models for propensity score matched groups, and evaluate their performance with a Monte Carlo simulation study. We found that the 4 models performed similarly with respect to model fit, bias of parameter estimates, Type I error, and power to test the treatment effect. To demonstrate a multigroup latent growth model with dummy treatment indicators, we estimated the effect of students changing schools during elementary school years on their reading and mathematics achievement, using data from the Early Childhood Longitudinal Study Kindergarten Cohort.  相似文献   

Testing Measurement Invariance Across Groups in Longitudinal Data: Multigroup Second-Order Latent Growth Model     

Eun Sook Kim  Victor L. Willson 《Structural equation modeling》2013,20(4):566-576

In latent growth modeling, measurement invariance across groups has received little attention. Considering that a group difference is commonly of interest in social science, a Monte Carlo study explored the performance of multigroup second-order latent growth modeling (MSLGM) in testing measurement invariance. True positive and false positive rates in detecting noninvariance across groups in addition to bias estimates of major MSLGM parameters were investigated. Simulation results support the suitability of MSLGM for measurement invariance testing when either forward or iterative likelihood ratio procedure is applied.  相似文献   

主轴承孔采用加工中心加工的质量和效率研究分析     

梁娟 《鸡西大学学报》2013,(11):51-52,62

针对发动机缸体主轴承孔加工精度高,公差规定严的要求,加工中采用缸体底面及底面两定位销孔定位的方式,选择合适的加工方式和刀具在加工中心上进行加工,可有效保证其加工精度。  相似文献   

Reliably Assessing Growth with Longitudinal Diagnostic Classification Models     

Matthew J. Madison 《Educational Measurement》2019,38(2):68-78

Recent advances have enabled diagnostic classification models (DCMs) to accommodate longitudinal data. These longitudinal DCMs were developed to study how examinees change, or transition, between different attribute mastery statuses over time. This study examines using longitudinal DCMs as an approach to assessing growth and serves three purposes: (1) to define and evaluate two reliability measures to be used in the application of longitudinal DCMs; (2) through simulation, demonstrate that longitudinal DCM growth estimates have increased reliability compared to longitudinal item response theory models; and (3) through an empirical analysis, illustrate the practical and interpretive benefits of longitudinal DCMs. A discussion describes how longitudinal DCMs can be used as practical and reliable psychometric models when categorical and criterion‐referenced interpretations of growth are desired.  相似文献   

对称法求积分     

王少英  王少彧 《铜仁学院学报》2007,1(5):93-95

总结了定积分、重积分、第一型曲线和曲面积分的对称性,结合具体例子说明利用积分对称性可使积分运算简单化。  相似文献   

Needs and Results in Virtual Reference Transactions: A Longitudinal Study     

Jaclyn McKewan  Scott S. Richmond 《The Reference Librarian》2017,58(3):179-189

  相似文献   

Following Young Students’ Understanding of Three Phenomena in which Transformations of Matter Occur     

Lena Löfgren  Gustav Helldén 《International Journal of Science and Mathematics Education》2008,6(3):481-504

In order to develop successful teaching approaches to transformations of matter, we need to know more about how young students develop an understanding of these processes. In this longitudinal study, we followed 25 students from 7 to 13 years of age in their reasoning about transformations of matter. The questions addressed included how the students’ understanding of transformations of matter changed and how we can make sense of individual learning pathways. In interviews performed once or twice every year the students described and explained three situations: fading leaves left on the ground, a burning candle, and a glass of water covered with a glass plate on which some mist had formed. When analysing the interviews, we found a common pathway of how the students’ ideas changed over the years in each one of the situations. When analysing individual student’s interviews with Ausubel’s assimilation theory we could discern subordinate, superordinate and combinatorial learning. How these findings can contribute to an improvement of teaching about transformations of matter is discussed.  相似文献   

湘南空间开发格局与经济发展思路   总被引：1，自引：0，他引：1  

谢守红 《衡阳师范学院学报》2001,22(4):34-38

湘南地处我国长江经济带与华南经济的结合部,交通便利,资源丰富,工农业生产具有一定基础。湘南空间开发应采取点轴布局模式,以衡阳、郴州、永川三市为核心增长极,以京广铁路沿线和湘桂铁路沿线为主要开发轴线,形成倒“V”字型格局。未来区域经济发展的思路是：加大开放力度,对接两广,呼应港澳;培育主导产业,增强工业经济实力。开发优势农产品资源,推进农业产业化进程;加快交通、商贸、旅游设施建设,形成大流通、大商贸格局。  相似文献