Conducting statistical tests with data from clustered school samples     

《International Journal of Research & Method in Education》2013,36(2):113-124

This article discusses issues associated with statistical testing conducted with data from clustered school samples. Empirical researchers often conduct tests of statistical inference on sample data to ascertain the extent to which differences exist within groups in the population. Typically, much school‐related data are collected from students. These data are hierarchical because students are nested within classes within schools. This article studies the influence of this nesting on tests of statistical significance conducted with the student as the unit of analysis. Theory that adjusts F‐test scores for nested data in multi‐group comparisons is presented and applied to a teacher interaction dataset. The article demonstrates the potential impact of data hierarchy on the results of statistical testing if clustering is ignored. Data analysis techniques that recognize the clustering of students in classes are essential, and it is recommended that either multilevel analysis or adjustments to statistical parameters be undertaken in studies involving nested data.  相似文献   

Validation and interpretation of Web users’ sessions clusters     

George Pallis  Lefteris Angelis  Athena Vakali 《Information processing & management》2007

Understanding users’ navigation on the Web is important towards improving the quality of information and the speed of accessing large-scale Web data sources. Clustering of users’ navigation into sessions has been proposed in order to identify patterns and similarities which are then managed in the context of Web users oriented applications (searching, e-commerce, etc.). This paper deals with the problem of assessing the quality of user session clusters in order to make inferences regarding the users’ navigation behavior. A common model-based clustering algorithm is used to result in clusters of Web users’ sessions. These clusters are validated by using a statistical test, which measures the distances of the clusters’ distributions to infer their dissimilarity and distinguishing level. Furthermore, a visualization method is proposed in order to interpret the relation between clusters. Using real data sets, we illustrate how the proposed analysis can be applied in popular application scenarios to reveal valuable associations among Web users’ navigation sessions.  相似文献   

Using cluster validation criterion to identify optimal feature subset and cluster number for document clustering     

Zheng-Yu Niu  Dong-Hong Ji  Chew Lim Tan 《Information processing & management》2007

This paper presents a cluster validation based document clustering algorithm, which is capable of identifying an important feature subset and the intrinsic value of model order (cluster number). The important feature subset is selected by optimizing a cluster validity criterion subject to some constraint. For achieving model order identification capability, this feature selection procedure is conducted for each possible value of cluster number. The feature subset and the cluster number which maximize the cluster validity criterion are chosen as our answer. We have evaluated our algorithm using several datasets from the 20Newsgroup corpus. Experimental results show that our algorithm can find the important feature subset, estimate the cluster number and achieve higher micro-averaged precision than previous document clustering algorithms which require the value of cluster number to be provided.  相似文献   

企业技术创新集群行为的行为生态学研究--一个分析框架的提出与构思   总被引：40，自引：1，他引：40  

刘友金  罗发友 《中国软科学》2004,19(1):68-72

行为生态学不仅是研究动物、生物集群行为的一门学问,而且也为研究人类及社会经济领域的集群行为提供了一种新视角、新理论和新方法。本文在分析企业技术创新的集群发展趋势、企业技术创新集群行为及其行为生态学特征的基础上,提出把行为生态学引入企业技术创新集群行为研究从而构建企业技术创新集群行为的行为生态学系统分析框架的构想,并着重对企业技术创新集群行为的行为生态学研究现状、研究思路和研究内容进行了初步的探讨。  相似文献   

知识产权集群互助担保的信用评价体系和方法     

马毅  李迟芳  左小明 《科技管理研究》2016,(19):196-201

描述一种新型知识产权集群互助担保融资研究的趋势、业务模式、资信评价特征及存在的问题,从而提出一种结合可拓层次分析、模糊综合的信用评价方法。该方法通过用区间数取代传统专家点值打分来构造可拓判断矩阵,能克服传统层次分析中专家模糊经验判断问题及判断矩阵的一致性不足问题,减少大量试算工作,并能更合理地计算知识产权集群互助担保融资项目的信用度。最后将其应用于某个商标权融资项目中,证明其实效性。  相似文献   

基于模糊聚类和模糊模式识别的数字图书馆个性化推荐研究     

王敏  嵇绍春 《现代情报》2016,36(4):52-56

为提高图书馆个性化推荐的效果,采用模糊聚类和模糊识别技术建立数字图书馆的个性化推荐系统。通过分析用户的信息素质、兴趣爱好、网络和电子资源检索情况,对读者进行数学模糊聚类分析,确定最佳阈值λ,得到最佳聚类。根据个体用户的基本情况进行模糊识别,由识别结果的归属给出针对当前用户的个性化推荐。实验结果表明,在模糊聚类与模糊识别基础上的个性化推荐方案是可行的和有效的,为创新数字图书馆个性化服务提供了一种新的方法。  相似文献   

应用模糊C均值聚类法判别同调机群正确性研究     

武艳  张莉莉  蒋志勋 《河北职业技术学院学报》2011,(4)

利用BPA软件以新英格兰10机39节点系统为例,验证模糊C均值聚类法判别同调机群的正确性。  相似文献   

基于蚁群模糊聚类算法的图像分割研究     

李玉梅 《天津职业院校联合学报》2011,13(2):78-81

论文提出了一种基于蚁群动态模糊聚类算法的计算机图像分割方法,有效地利用蚁群算法的聚类分析能力,克服了FCM算法对初始化的敏感,动态地确定了聚类数目和中心。然后利用蚁群聚类算法得到的模型进行修改,再进行模糊聚类弥补蚁群算法的不足。最后将该算法应用到计算机图像分割技术。对比实验表明,该算法实验表明该算法速度快、划分特性好,可以准确地分割出目标。  相似文献   

新时期科技学术期刊英文出版平台建设   总被引：1，自引：1，他引：0  

王晓峰  邓迎  徐雁龙  杨蕾 《编辑学报》2019,31(2):200-203

随着中国英文科技学术期刊出版数量快速增加,出版平台建设益发重要,而且全球范围内开放获取需求的不断提高也为平台建设提出了新的要求。以新时期建设科技学术期刊英文平台为目标,探讨了建设过程中需要注意的若干问题,其中包括平台的整体规划、平台建设与创办一流期刊、平台与前后端系统的衔接、平台建设与运营的关系、建设平台的学科特色等方面的内容。期刊出版平台的建设要结合学科特色,推动期刊的集群化、数字化出版,最终把中国科技学术期刊出版事业做大做强。  相似文献   

煤炭行业科技期刊服务科研的创新实践     

宫在芹  朱拴成 《编辑学报》2019,31(6):669-672

新时代各种新媒介形态和技术平台的兴起为科技期刊提升服务科研的能力创造了条件。科技期刊应该打破传统论文单一渠道传播、一次性消费的发展难题,积极与平台和新技术融合。文章介绍煤炭行业期刊以中国煤炭行业知识服务平台为支撑,采用增强出版、科普新闻、知识问答、专题库、知识包、流媒体加工、视频策划与加工等媒体融合方式为科研提供服务的实践。这些措施显著提升了煤炭行业科技期刊为科研服务的能力,可为其他期刊及刊群提供参考。  相似文献