A Review of Methods for Missing Data

This paper reviews methods for handling missing data in a research study. Many researchers use ad hoc methods such as complete case analysis, available case analysis (pairwise deletion), or single-value imputation. Though these methods are easily implemented, they require assumptions about the data that rarely hold in practice. Model-based methods such as maximum likelihood using the EM algorithm and multiple imputation hold more promise for dealing with difficulties caused by missing data. While model-based methods require specialized computer programs and assumptions about the nature of the missing data, these methods are appropriate for a wider range of situations than the more commonly used ad hoc methods. The paper provides an illustration of the methods using data from an intervention study designed to increase students’ ability to control their asthma symptoms.     

基于DIV＋CSS的网页布局模式

DIV＋CSS是目前进行网页布局的主要技术之一．介绍了DIV＋CSS网页布局技术,并举例说明基于DREAMWEAVER平台使用DIV＋CSS网页布局技术进行网页设计的操作方法和过程．     

基于网络环境的差异教学设计

差异教学主张以学习者差异为出发点展开教学,而在网络上应用差异教学,已经成为许多学者和教师所关注的问题。通过对差异教学中各种"差异"因素的深入研究,提出基于网络环境的差异教学设计模式,对各环节进行具体设计并提出设计案例。     

高校计算机教学创新能力培养问题研究

根据高校计算机教学现状,对高校计算机教学创新能力培养问题进行了研究．分析了生源质是、垛程没置、学生就业等影响．目前高校计算机教学的主要问题,提出了重视职业能力、模块化课程、网络资源的利用等计算机课程体系改革的思路,探讨了学生创新能力的培养、自学能力培养和“终身学习”的意识．     

Differentiated instruction: are Hong Kong in-service teachers ready?

Differentiated instruction (DI) is nothing new and is believed to be an effective research-based strategy to cater for learner diversity. Differentiation involves finding multiple ways to structure a lesson so that each student is provided with an opportunity to work at a moderately challenging level. Previous studies, however, found that teachers were not well prepared and insufficiently equipped with skills and knowledge about DI. In the recent Hong Kong curriculum reform, DI has been highlighted as one of the ways to catering to learner diversity. The purpose of the study is to examine in-service teachers’ readiness for using DI strategies and perceived challenges in its implementation. Using a mixed-methods design, a questionnaire was used to investigate teachers’ perceived readiness for and obstacles toward using DI strategies, as followed by semi-structured focus group interviews that were done to in-service teachers of two schools. Qualitative data as obtained from the interviews was used to explain the quantitative data. With the use of factor analysis, two factors were identified in the survey, including Factor 1 Teacher-centred approach and Factor 2 Student-centred approach. Findings indicated that teachers generally tended to be ready for using DI strategies; however, they were more ready for using teacher-centred approach. Three perceived obstacles toward DI were identified: class size and diversity, time, and understanding of teaching strategies. Implications for curriculum development, professional development and research directions will be discussed at the end of the paper.     

也释“老天拔地”

“老天拔地”是东北方言,意为“上了年纪,动作不灵活”,还指一些人虽然不是老年人,但是其动作行为迟缓,像个老年人一样。