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21.
Middle school students (n = 354) were tested for their understanding of the control of variables strategy (CVS) 2.5 years after participating in a study comparing three different interventions for teaching CVS. The key finding was that the pattern of effects observed in the 4th grade continued to be observed in the 6th grade. This was because (a) students who had mastered CVS in the 4th grade were likely to continue to perform at mastery levels in the 6th grade whereas (b) the learning of students who had not mastered CVS in 4th grade was independent of the teaching intervention they had received in the 4th-grade study. These findings demonstrate that a brief intervention of direct instruction in CVS can produce long-lasting learning of the principle of controlling variables.  相似文献   
22.
23.
While much research has been directed at the variables critical to successful R&D of new products on the one hand and high-technology products on the other, much less work has been directed at those factors crucial to the success of these products when the firm enters the international marketplace. This study surveys Finnish high-technology firms and variables related to the properties of the company and their association with successful versus unsuccessful attempts to enter the international marketplace. Relationship between firm characteristics – type of industry, size of the company, background of key personnel, export intensity and experience in product launches – and success/failure in the product launches is investigated. The generalizability of the findings is also discussed.  相似文献   
24.
实验设备管理中几种决策的理论研究   总被引:2,自引:0,他引:2  
该文章就实验设备维护中怎样配备恰当的维修人数问题,以及如何选择最佳管理模式问题进行了深入的研究,用数学的方法从理论上解决了这些问题。  相似文献   
25.
通过对反生产行为控制策略文献的研究,以组织公正效果变量为基础,通过前人对组织公正的三维度、组织公正效果变量的三维度,结合反生产行为人际—组织二维度构建组织公正对反生产行为的影响机制,并依据该机制提出有效的管理策略和步骤。  相似文献   
26.
函数极值的存在性及判别方法是微分的重要应用之一.文章就三元函数给出了判别极值的存在的一个必要条件和充分条件.  相似文献   
27.
La incidencia de las competencias lingüistícas del escolar sobre las adquisiciones escolares en las demás áreas del currículum es una realidad que todos los maestros pueden comprobar día a día. En este trabajo se investiga esa incidencia, medida a través de la variable fracaso escolar, y sus resultados podrían permitir extraer algunos principios de intervención educativa precoz en algunos aspectos del lenguaje cruciales para la escolaridad posterior.  相似文献   
28.
This article discusses replication sampling variance estimation techniques that are often applied in analyses using data from complex sampling designs: jackknife repeated replication, balanced repeated replication, and bootstrapping. These techniques are used with traditional analyses such as regression, but are currently not used with structural equation modeling (SEM) analyses. This article provides an extension of these methods to SEM analyses, including a proposed adjustment to the likelihood ratio test, and presents the results from a simulation study suggesting replication estimates are robust. Finally, a demonstration of the application of these methods using data from the Early Childhood Longitudinal Study is included. Secondary analysts can undertake these more robust methods of sampling variance estimation if they have access to certain SEM software packages and data management packages such as SAS, as shown in the article.  相似文献   
29.
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.  相似文献   
30.
本文的研究目的是了解知识型员工的区域间流动的三类要素的关系,即人口统计变量、价值观和区域性因素偏好的关系。通过对625名知识型员工的问卷调查,获得人口统计变量、价值观和区域性因素的偏好的相关数据,对其进行独立样本T检验、单因素方差分析和相关分析,得出了人口统计变量、价值观和区域性因素偏好部分相关的结论。  相似文献   
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