The Redirection: An Indicator of How Teachers Respond to Student Thinking

Responsive teaching occurs when teachers take up and respond to their students’ ideas during instruction (J. L. Pierson, 2008). Although responsive teaching is gaining recognition as an effective strategy for encouraging student learning, few methods of analysis are capable of characterizing the different ways in which teachers take up their students’ ideas in the moment. This article presents and exemplifies a new methodological construct, the redirection, which provides researchers with a means of detecting nuanced differences in how teachers respond to their students’ thinking. The redirection construct emerged via systematic discourse analysis of 1 science teacher’s classroom discussions during 3 implementations of an inquiry-based module on the water cycle. Redirections are defined as instances when a teacher invites students to shift or redirect their attention to a new locus. Such shifts reflect different types of teacher responsiveness and, as such, can be used to capture the different ways in which teachers take up their students’ ideas. This article presents a comprehensive coding scheme for the redirection, in addition to segments of classroom discourse to exemplify each redirection coding category. A comparison of 3 5th-grade teachers using the construct provides an illustrative example of the type of analysis such a coding scheme affords learning sciences researchers.     

用于甚低比特率视频编码的三维小波变换

A new improved Goh's 3-D wavelet transform(WT) coding scheme is presented in this paper. The new scheme has great advantages including a simple code structure, low computation cost and good performance in PSNR, compression ratios and visual quality of reconstructions, when compared to the other existing 3-D WT coding methods and the 2-D WT-based coding methods. The new 3-D WT coding scheme is suitable for very low bit-rate video coding.     

3 D Wavelet Transform for Very Low Bit Rate Video Coding

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Conceptions of teaching held by academic teachers

This study examines conceptions of teaching held by academic teachers in the fields of science and social science, in two universities: a distance university in the UK and a traditional one in Australia. A five level classification of conceptions of teaching is proposed. A process of arriving at this scheme is discussed and a formalised coding system is presented which helps to delimit, with greater confidence, the boundaries of each conception, and helps to order conceptions, to compare conceptions proposed by other researchers, and to place individuals within conceptions. The same coding system is then used to define the concepts of student-centered and teacher-centered approaches to teaching. There is a strong suggestion that teaching conceptions are context-dependent.     

LDPC based differential unitary space-frequency coding for MIMO-OFDM systems

INTRODUCTION Unitary space-time modulation (USTM) (Hochwald and Marzetta, 2000) has been shown to be ideally suited for Rayleigh flat fading channels when there is no CSI. And for continuously changing fading channels, differential unitary space-time modulation (DUSTM) was proposed in Hochwald and Sweldens (2000). However, the performance of DUSTM de-grades considerably in frequency-selective fading channels often encountered in broadband wireless communications. Hence concatena…     

Research Trends in Technology-Enhanced Chemistry Learning: A Review of Comparative Research from 2010 to 2019

Chemistry is a subject which involves a number of abstract concepts, making it a difficult and frustrating learning process for many students. Educators and researchers believe that technology could provide an opportunity to address this problem. However, it is challenging to find a model for appropriately and successfully integrating technology into chemistry education. Therefore, in this study, a review was conducted on the technology-enhanced chemistry learning studies published in Social Science Citation Index (SSCI) journals from 2010 to 2019. This study searched the target articles from the Web of Science (WOS) database and excluded those studies that did not adopt a comparative research design. Finally, 60 studies were included in this research trend analysis. A coding scheme was developed for the types of technology, the types of learning tools, the roles of technology in chemistry learning, learning topics, learning environments, participants, research designs, and the learning outcomes the researchers evaluated. From the analysis results, it was found that (1) inorganic chemistry and physical chemistry courses were the main learning topics, while the formal classroom was most often referred to as the research setting. The most frequently discussed issue was students’ learning achievement. (2) Regarding technology integration, offering students learning content through personal computers was the main activity mode. The technology was used for lower-level implementation, that is, providing supplementary materials for students. (3) Finally, using keyword analysis, it is possible to extract the recent concerns of the researchers, and from the results of the study, it is clear that the researchers are placing increasing emphasis on learners’ experience and skill development in the learning process. Accordingly, this study highlights the features of the research trends and then provides suggestions for researchers in the technology-enhanced chemistry learning field.

     

口试评分规范化与信度研究

口语考试的效度较高,信度却比较低。但没有信度,效度也不可能真正得到保证。因此,如何提高口试的信度,是很多测试研究者普遍关注的问题。本文通过描述清华大学英语水平考试中口试部分的评分规范化与评分员培训,对如何规范评分以提高口试信度这一问题进行讨论。     

体验取样法在情绪研究中的应用优势

情绪研究的难题在于其具有动态变化性、情境依存性和个体差异性三大特征,这亟需研究者在对情绪及其相关变量测查时做特别的考量,而传统的情绪研究方法在这些方面存在欠缺。在这种情况下,体验取样法在情绪研究中具有得天独厚的优势:首先,它可以在一定时间跨度内对情绪事件进行即时、连续、重复地测量,降低了潜在记忆偏差和个人偏好的影响;其次,它把情绪事件置于真实的社会环境中,增强了研究的生态效度;另外,它丰富庞大的数据采集量能够从多水平、多角度、多变量分析个体情绪的整个变化过程。随着情绪研究的不断深入,体验取样法将会得到越来越多的运用。     

基于TPACK框架的话语分析:师范生在教学设计过程中关注什么?

教师的信息技术整合能力一直是国内外研究者关注的问题。整合技术的学科教学法(TechnologicalPedagogical Content knowledge,TPACK)概念的提出为这方面的研究提供了理论框架。2010年12月2日至19日,上海市某高校开展了一次职前教师教育微型课程。在之前的一项研究中,研究者使用前后测量表的数据,分析了微型课程前后师范生TPACK水平的变化情况。在随后的研究中,研究者深入到微型课程的实施过程中,对师范生的话语进行记录,并按照TPACK框架进行话语编码和分类。通过统计各类话语的比重,从班级、小组两个层面呈现出师范生在近似真实的教学设计过程中的关注焦点的变化情况,从而为以培养教师的信息技术整合能力为目标的教师教育课程提供建议。     

基于离散对数与零空间的合成 HMAC 网络编码方案

为了降低中间节点编码转发机制给网络编码系统带来的污染攻击风险,通过分析零空间网络编码理论研究成果,提出基于离散对数公钥机制与零空间对称密钥机制的合成 HMAC 方案。对该方案进行安全性分析,并在每个数据包签名长度 L = 10 、每代数据包消息条数 m = 50 等条件下进行实验。结果表明,该方案计算效率相比基于经典密码学的具有抗伪造能力与可验证性的 HSS 方案提高了 3 倍以上,而且恶意节点伪造数据包成功通过其它节点验证的概率,相比基于零空间理论的具有同态性与较高计算效率的 NS-HMAC 方案降低了 qL - 1 倍。因此,基于离散对数公钥机制与零空间对称密钥机制的合成 HMAC 方案不仅提高了计算效率,还提高了安全性。     

How is the approach to teaching at secondary school related to first-year university achievement?

The study presented here is an elaboration on recent educational effectiveness research focusing on long-term school effects. Central in this study is the approach to teaching at secondary schools and its relation to student perception of the fit between school and university and 1st-year academic achievement. Based on previous research, a coding scheme is developed to classify pre-university schools based on the approach to teaching in the upper 3 years. Schools are scored according to this coding scheme and grouped with hierarchical cluster analysis, resulting in 3 groups: 1 characterized by a strong teacher-regulation approach, 1 with a shared regulation approach to learning, and 1 intermediate group. Multiple analysis of covariance shows differences between school clusters regarding student 1st-year achievement in soft science programmes.     

Productive group engagement in cognitive activity and metacognitive regulation during collaborative learning: can it explain differences in students’ conceptual understanding?

This paper addresses the nature and significance of productive engagement in cognitive activity and metacognitive regulation in collaborative learning tasks that involve complex scientific knowledge. A situative framework, combining the constructs of social regulation and content processing, provided the theoretical basis for the development of a comprehensive coding scheme for interactive data analysis. An empirical study was conducted with two groups of university students working on two science-learning tasks. It examined the function of metacognitive regulation to control the flow of cognitive activity, and the extent to which group differences in cognitive and metacognitive regulation processes during collaborative learning could explain differences in the groups’ learning outcomes. The findings provide validation of the framework and its derived coding scheme. An example of a way in which a group engages in socially shared metacognitive regulation is presented to demonstrate how the coding scheme was applied to the data. Theoretical and empirical implications of the findings are discussed.     

What time-series designs may have to offer educational researchers

The promise of time-series designs for educational research and evaluation is reviewed. Ten time-series designs are presented and discussed in the context of threats to internal and external validity. The advantages and disadvantages of various visual and statistical data-analysis techniques are presented. It is argued that time-series research paradigms are useful when researchers (a) wish to involve a single subject in experimental research (individuals as units of analysis) or conduct program-evaluation studies (aggregates as units of analysis), (b) are interested in nearly continuous measurement, (c) cannot meet conventional design and statistical assumptions, or (d) wish to specify individual differences through N = 1 research strategies. It is also suggested that more research endeavors be devoted to combining unique characteristics of time-series research with conventional multi-unit paradigms.     

Representing students' thinking about nutrient cycling in ecosystems: bidimensional coding of a complex topic

This study addresses the question of how to represent students' thinking about a complex topic in a way that is most useful to guide curriculum development, instructional decisions, and assessment of student learning. The development of a coding scheme that represents students' ideas along two dimensions, compatibility with expert propositions and elaboration of ideas, is described and applied to the analysis of interviews with four pairs of urban fifth- and sixth-grade students. Results indicate that decomposition is a linchpin concept for building an understanding of nutrient cycling, and that ideas which relate to children's natural framework theories provide a generative foundation for further learning. Finally, it is suggested that the elaboration dimension of the bidimensional coding scheme provides an indication of students' possession of valuable scientific habits of mind. © 1996 John Wiley & Sons, Inc.     

Assessing metacognitive activities: the in-depth comparison of a task-specific questionnaire with think-aloud protocols

Teaching and assessing metacognitive activities are important educational objectives, and teachers are calling for efficient instruments. The advantages of questionnaires in measuring metacognitive activities are obvious, but serious validity issues appear. For example, correlations of questionnaire data with think-aloud measures are generally moderate to low. An explanation may be that these questionnaires are not constructed in line with the metacognitive activities measured by the think-aloud method. In the present study, a questionnaire is constructed based directly on a taxonomy for coding think-aloud protocols. Twenty ninth-graders studied a text while thinking aloud, after which they immediately received the questionnaire. The overall correlation between the questionnaire and the think-aloud protocols (r?=?0.63) was promising. However, scale and item analyses clearly demonstrate some new validity issues. Comparing the questionnaire and the think-aloud results, the students seem to report overt metacognitive activities corresponding more with their behavior reported in the protocols than covert ones. In-depth explorations are presented.     

Wavelet Adaptive Bitzerotree Coding for Video

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Validity in quantitative content analysis

Over the past 15 years, educational technologists have been dabbling with a research technique known as quantitative content analysis (QCA). Although it is characterized as a systematic and objective procedure for describing communication, readers find insufficient evidence of either quality in published reports. In this paper, it is argued that QCA should be conceived of as a form of testing and measurement. If this argument is successful, it becomes possible to frame many of the problems associated with QCA studies under the well-articulated rubric of test validity. Two sets of procedures for developing the validity of a QCA coding protocol are provided, (a) one for developing a protocol that is theoretically valid and (b) one for establishing its validity empirically. The paper is concerned specifically with the use of QCA to study educational applications of computer-mediated communication.     

协作学习交互分析方法之反思

当今教育理念已经从关注个体知识建构转向关注群体知识建构。协作学习作为一种群体建构的方式,已经成为各级各类教育特别是高等教育的一种主要学习方式。交互是协作学习的基本活动单元,也是理解协作学习本质的关键。交互分析是探究协作学习规律、把握协作学习过程变化的核心,也是诊断学习者对教学目标掌握程度的依据。交互分析研究的重心已经从交互的各种影响因素转移到小组交互过程的研究。但目前关于交互过程的研究主要集中在宏观的交互模式、成员关系、交互行为特征等方面,还存在对交互过程的分析粒度过粗、视交互为静态的过程、以及缺乏客观、有效的分析方法和工具等问题。目前已有的9种协作学习交互分析方法大多从言语行为的视角对交互过程进行分析,在划分分析单元、确定客观且可重用的编码体系,以及保证分析方法的信效度方面面临诸多挑战。基于信息流的协作学习交互分析方法着眼于整体,注重过程,并用新的效标即信息流所映射的目标知识网络图的总激活量来预测交互效果,信效度较高,可能成为一种有前景的交互分析方法。