Assessing Model Similarity in Structural Equation Modeling

Two models can be nonequivalent, but fit very similarly across a wide range of data sets. These near-equivalent models, like equivalent models, should be considered rival explanations for results of a study if they represent plausible explanations for the phenomenon of interest. Prior to conducting a study, researchers should evaluate plausible models that are alternatives to those hypothesized to evaluate whether they are near-equivalent or equivalent and, in so doing, address the adequacy of the study’s methodology. To assess the extent to which alternative models for a study are empirically distinguishable, we propose 5 indexes that quantify the degree of similarity in fit between 2 models across a specified universe of data sets. These indexes compare either the maximum likelihood fit function values or the residual covariance matrices of models. Illustrations are provided to support interpretations of these similarity indexes.     

Explaining the substantial inter-domain and over-time correlations in student achievement: the importance of stable student attributes

Multi-domain and longitudinal studies of student achievement routinely find moderate to strong correlations across achievement domains and even stronger within-domain correlations over time. The purpose of this study is to examine the sources of these patterns analysing student achievement in 5 domains across Years 3, 5 and 7. The analysis is of longitudinal population data of over 22,000 students and utilizes fixed-effects models to incorporate stable general and domain-specific latent factors. These latent factors correspond to a general cognitive-ability-like factor and specific aptitudes in particular, or types of, subject areas. The preferred model incorporates both general and domain-specific latent factors with stronger effects for the general factor, although the domain-specific factors are particularly strong for spelling and numeracy. When taking into account general and domain-specific latent factors, the effects of student’s socioeconomic status (SES) and school SES are trivial.     

主应力轴旋转情况下土的各向异性理论研究进展

从理论方面,对国内外主应力轴旋转情况下土的各向异性研究进行了对比和总结,并提出了一些研究建议。指出在理论方面,应当对屈服面方程采用应力分量表示的模型在三维空间里进行屈服面性状的描述,同时考虑不同加载方向下屈服面的变化特性以及旋转硬化的问题,并应开展对加载方向变化时土体屈服面变化特性的实验研究及理论验证。     

Software review

STATISTICA 5.0. StatSoft, 2325 East 13th Street, Tulsa, OK 74104, (918) 583–4149. $995 retail, academic site license—$2,000 for 10 copies. Requirements: 386 or better, 4 Meg RAM, Microsoft Windows 3.1 or 95.     

Fitting Nonlinear Latent Growth Curve Models With Individually Varying Time Points

Individual growth trajectories of psychological phenomena are often theorized to be nonlinear. Additionally, individuals’ measurement schedules might be unique. In a structural equation framework, latent growth curve model (LGM) applications typically have either (a) modeled nonlinearity assuming some degree of balance in measurement schedules, or (b) accommodated truly individually varying time points, assuming linear growth. This article describes how to fit 4 popular nonlinear LGMs (polynomial, shape-factor, piecewise, and structured latent curve) with truly individually varying time points, via a definition variable approach. The extension is straightforward for certain nonlinear LGMs (e.g., polynomial and structured latent curve) but in the case of shape-factor LGMs requires a reexpression of the model, and in the case of piecewise LGMs requires introduction of a general framework for imparting piecewise structure, along with tools for its automation. All 4 nonlinear LGMs with individually varying time scores are demonstrated using an empirical example on infant weight, and software syntax is provided. The discussion highlights some advantages of modeling nonlinear growth within structural equation versus multilevel frameworks, when time scores individually vary.     

Activity theory: A framework for design and reporting on research projects based on ICT

We propose using activity theory as a basis for designing and reporting on research projects that focus on information and communication technology (ICT) as a means to support educational processes. Adopting the theory, we describe teaching/learning activities mediated by ICT using a three level analysis: epistemological, methodological, social assistance. The analysis has been applied to the design and reporting of projects in both mathematics education at primary school level and training in technical innovation in commercial enterprises.     

环境变动、非营利组织创新与组织绩效的关系研究

将组织创新的研究视野拓展至我国不同类型的非营利组织,构建了环境变动、非营利组织创新与组织绩效间关联的概念模型,并以浙江省的公益型和互益型非营利组织为样本对概念模型进行了实证检验。研究结果表明,环境变动对非营利组织创新有直接推动作用,非营利组织创新对组织绩效也有直接正向影响;虽然环境变动对非营利组织绩效的直接影响并不显著,但非营利组织通过采用组织创新战略,可以使环境变动对组织绩效间接产生积极的影响。     

国外公司治理结构的模式和发展趋势

通过研究国外公司治理结构的模式的特点、利弊，分析国外公司治理结构的发展趋势，结合中国中小民营企业的特点，提出了建立中国中小民营企业治理结构的思路。     

生态学视角下基于熵权可拓模型的山西省人才聚集预警研究

基于生态学的理论视角,结合熵权和物元可拓模型的相关理论,以山西省为例,从生态学的角度构建人才聚集预警的指标体系,建立人才聚集预警熵权可拓模型对山西省2006—2013年的人才预警状况进行实证分析,结果表明:山西省人才聚集处于中度预警状态,制度生态因子、社会生态因子、经济生态因子的推动作用促进山西省人才聚集预警度呈现转好的局面,文化生态因子和教育生态因子阻碍了人才聚集的平衡性发展,出现了向低等级转移的趋势。为防止山西人才聚集的非经济现象更加突出提供理论依据,为山西省人才聚集的良性发展提供参考性意见。     

协作研发网络成员间重复合作对二元式创新的影响——技术能力与环境动态性的调节作用

基于中国制造业119家上市公司2004—2013年非平衡面板数据,采用负二项回归模型实证检验协作研发网络成员间重复合作对二元式创新的影响,并从组织的内外部情境出发探讨内部技术能力及外部环境动态性对重复合作与企业二元式创新关系的调节作用。研究表明:重复合作与利用式创新、探索式创新均呈倒U型关系,重复合作程度的提升将先抑制探索式创新,再抑制利用式创新;同时,技术能力与环境动态性均对重复合作与企业二元式创新之间的关系具有显著的调节作用。