Reliability,Dimensionality, and Internal Consistency as Defined by Cronbach: Distinct Albeit Related Concepts

This article uses definitions provided by Cronbach in his seminal paper for coefficient α to show the concepts of reliability, dimensionality, and internal consistency are distinct but interrelated. The article begins with a critique of the definition of reliability and then explores mathematical properties of Cronbach's α. Internal consistency and dimensionality are then discussed as defined by Cronbach. Next, functional relationships are given that relate reliability, internal consistency, and dimensionality. The article ends with a demonstration of the utility of these concepts as defined. It is recommended that reliability, internal consistency, and dimensionality each be quantified with separate indices, but that their interrelatedness be recognized. High levels of unidimensionality and internal consistency are not necessary for reliability as measured by α nor, more importantly, for interpretability of test scores.     

Interim Assessments as a Strategy for Improvement: Easier Said Than Done

This essay provides an overview of the papers contained in this issue of the Peabody Journal of Education. In it, the author notes for policymakers especially issues and concerns that emerge from the use of formative assessments geared towards education improvement. While the intent of such assessments is lead to improved overall instruction and improved outcomes, he stresses that this is not a passive act that rests solely on testing children, providing their teachers and school leaders with data, and then hoping improvement will occur.     

How Well Does the Sum Score Summarize the Test? Summability as a Measure of Internal Consistency

Many researchers use Cronbach's alpha to demonstrate internal consistency, even though it has been shown numerous times that Cronbach's alpha is not suitable for this. Because the intention of questionnaire and test constructers is to summarize the test by its overall sum score, we advocate summability, which we define as the proportion of total test variation that is explained by the sum score. This measure is closely related to Loevinger's H. The mathematical derivation of summability as a measure of explained variation is given for both scale and dichotomously scored items. Using computer simulations, we show that summability performs adequately and we apply it to an existing productive vocabulary test. An open‐source tool to easily calculate summability is provided online ( https://sites.google.com/view/summability ).     

Digital ITEMS Module 2: Scale Reliability in Structural Equation Modeling

In this ITEMS module, we frame the topic of scale reliability within a confirmatory factor analysis and structural equation modeling (SEM) context and address some of the limitations of Cronbach's α. This modeling approach has two major advantages: (1) it allows researchers to make explicit the relation between their items and the latent variables representing the constructs those items intend to measure, and (2) it facilitates a more principled and formal practice of scale reliability evaluation. Specifically, we begin the module by discussing key conceptual and statistical foundations of the classical test theory model and then framing it within an SEM context; we do so first with a single item and then expand this approach to a multi‐item scale. This allows us to set the stage for presenting different measurement structures that might underlie a scale and, more importantly, for assessing and comparing those structures formally within the SEM context. We then make explicit the connection between measurement model parameters and different measures of reliability, emphasizing the challenges and benefits of key measures while ultimately endorsing the flexible McDonald's ω over Cronbach's α. We then demonstrate how to estimate key measures in both a commercial software program (Mplus) and three packages within an open‐source environment (R). In closing, we make recommendations for practitioners about best practices in reliability estimation based on the ideas presented in the module.     

ANNUAL INDEX Volume 71 Fall 2002-Summer 2003

In this study, the authors aimed to examine 8 of the different methods for computing confidence intervals around alpha that have been proposed to determine which of these, if any, is the most accurate and precise. Monte Carlo methods were used to simulate samples under known and controlled population conditions wherein the underlying item distribution is nonnormal and when the items’ responses are those of rating scales rather than dichotomous items. Overall, one can conclude that, despite concerns expressed over the use of Fisher's method for coefficient alpha, in general, it actually outperformed the other methods. Larger sample sizes and larger coefficient alphas also resulted in better band coverage, whereas smaller number of items resulted in poorer band coverage.     

Evaluation of Dimensionality in the Assessment of Internal Consistency Reliability: Coefficient Alpha and Omega Coefficients

In the lead article, Davenport, Davison, Liou, & Love demonstrate the relationship among homogeneity, internal consistency, and coefficient alpha, and also distinguish among them. These distinctions are important because too often coefficient alpha—a reliability coefficient—is interpreted as an index of homogeneity or internal consistency. We argue that factor analysis should be conducted before calculating internal consistency estimates of reliability. If factor analysis indicates the assumptions underlying coefficient alpha are met, then it can be reported as a reliability coefficient. However, to the extent that items are multidimensional, alternative internal consistency reliability coefficients should be computed based on the parameter estimates of the factor model. Assuming a bifactor model evidenced good fit, and the measure was designed to assess a single construct, omega hierarchical—the proportion of variance of the total scores due to the general factor—should be presented. Omega—the proportion of variance of the total scores due to all factors—also should be reported in that it represents a more traditional view of reliability, although it is computed within a factor analytic framework. By presenting both these coefficients and potentially other omega coefficients, the reliability results are less likely to be misinterpreted.     

从语法和语言学看have sth done中sth与done的内在关系

使役动词have的被动语态have sth done在国内语法书中都只是略有涉及,简单地介绍该短语的句式结构、用法和表达意义等。但是从语言学的角度来看,对该短语中的sth是有限制要求的。旨在语法基础上,从语言学视角,探讨sth与done之间的内在关系。     

Delimiting Coefficient α from Internal Consistency and Unidimensionality

I discuss the contribution by Davenport, Davison, Liou, & Love (2015) in which they relate reliability represented by coefficient α to formal definitions of internal consistency and unidimensionality, both proposed by Cronbach (1951). I argue that coefficient α is a lower bound to reliability and that concepts of internal consistency and unidimensionality, however defined, belong to the realm of validity, viz. the issue of what the test measures. Internal consistency and unidimensionality may play a role in the construction of tests when the theory of the attribute for which the test is constructed implies that the items be internally consistent or unidimensional. I also offer examples of attributes that do not imply internal consistency or unidimensionality, thus limiting these concepts' usefulness in practical applications.     

Facilitating metacognitive talk: a research and learning tool

This paper describes a research tool which aims to gather data about pupils' views of learning and teaching, with a particular focus on their thinking about their learning (metacognition). The approach has proved to be an adaptable and effective technique to examine different learning contexts from the pupils' perspective, while also acting as an aid to reflective dialogue between pupils and teachers as part of the teaching and learning process. A range of templates have been created as psychological or semiotic tools. They form the basis of a mediated interview by providing an image of the learning environment or activity on which the research is focused. The image then becomes the stimulus for a three‐way interaction between the researcher (or the teacher), the pupil and the template. This paper provides examples from a number of research projects where the technique has been used to gather data in classrooms.     

Leading the Multiethnic School: Research Evidence on Successful Practice

This article reports findings from a study of principals in five multiethnic schools in England. Findings are presented in terms of the major priorities or values held by the principals, the strategies they instituted to bring their priorities to life, and some of the challenges they continue to face in this endeavor. The principals involved believed that they could make a difference in their schools and were proactive, but at the same time, realistic about what could be achieved. They distinguished themselves by aggressively tackling disadvantages related to ethnicity, racism, culture, and poverty.     

地方性文化的力量：张謇教育思想与区域县中繁荣

县中是县域教育的支柱和地方发展的希望所在,但近年来县中的师生与制度结构失去了比较优势,陷入困境。在建设教育强国的蓝图下,县中如何重整旗鼓？本文基于对全国知名县中聚集地——南通市的调查,借助强文化范式框架,探讨张謇教育思想何以成为一种与结构力量互补的地方文化力量助推县中发展。张謇教育思想在改革开放初的南通崛起叙事中被激活,锚定科教兴市的第一战略选择,使政府注意力优先分配于教育,从而塑造了县中的良好外部生态和主体积极实践,两者的适配进而带来区域县中繁荣。从文化社会学视角出发,将县中讨论转向地方性,揭示县中发展离不开由本土社会文化传统和资源产生的强大动力,这为其他地方教育振兴提供了启示。     

杨万里与“诚斋体”－杨万里诗学述评

杨万里的诗学思想以对江西诗学的修正标志着宋代诗学的转型。他的诗学观包括了触物感兴、悟入活法、味外之味三个方面,他力图从自然万象中汲取灵感,创造出一种轻清活泼而又趣味隽永的新的诗风,被称为“诚斋体”。这种诗体虽对江西有所突破与变革,但仍与之有内在的联系,本质上仍是“内圣”人格的一种表现。他对江西诗法,尤其是它的句法论,也多所继承,故后人仍目之为江西派诗人。     

Digital ITEMS Module 1: Reliability in Classical Test Theory

In this ITEMS module, we provide a two‐part introduction to the topic of reliability from the perspective of classical test theory (CTT). In the first part, which is directed primarily at beginning learners, we review and build on the content presented in the original didactic ITEMS article by Traub and Rowley (1991). Specifically, we discuss the notion of reliability as an intuitive everyday concept to lay the foundation for its formalization as a reliability coefficient via the basic CTT model. We then walk through the step‐by‐step computation of key reliability indices and discuss the data collection conditions under which each is most suitable. In the second part, which is directed primarily at intermediary learners, we present a distribution‐centered perspective on the same content. We discuss the associated assumptions of various CTT models ranging from parallel to congeneric, and review how these affect the choice of reliability statistics. Throughout the module, we use a customized Excel workbook with sample data and basic data manipulation functionalities to illustrate the computation of individual statistics and to allow for structured independent exploration. In addition, we provide quiz questions with diagnostic feedback as well as short videos that walk through sample exercises within the workbook.     

The start-up phase in a research and development work project: A foundation for development

The article is based on a research and development work project (R&D project) conducted in a Norwegian lower secondary school. The purpose of the text is to describe the researchers’ and teachers’ roles during the initial phase of such a project, and what this phase and the close cooperation between the researcher and teachers mean for the progress of the project. The reader will see how the participating teachers modify their attitudes to the project throughout the start-up phase. This phase is outlined by means of empirical data. The study shows how such a project challenges the researchers’ communicative, social and knowledge competence. Furthermore, teachers have to see the need for development and willingly participate in developmental processes, listening to and using researchers as resource persons, if a start-up phase is to be successful for subsequent development in the project.     

Education and training: Impacts on farm management practice

Abstract

This paper presents the results of a large Australia‐wide survey which collected farm financial information and information about changes to farm‐management practices, as well as information about education and training, and a smaller survey of farmers who attended one of three training courses for farmers. The paper considers the relationship between education and training outcomes at macro and micro levels. At the macro level, education and training as well as prompts for change are considered, while at the micro level the influence of training on changes to practice is examined. Education and training enhance farmers’ ability and willingness to make successful changes to their management practice. The training program is generally only one of several factors which influence participants to make changes in their practice. Training events are opportunities for interaction between participants and with expert trainers. This interaction assists in altering values and attitudes toward new practices.     

基于杨赤中滤波推估插值法的DEM坡度、坡向的分析

将高程观测值看作是一种包含期律性变化和随机性变化的复合变量,应用杨赤中滤波法求其二项系数加权游动平均,建立估值数学模型,求得各格网点高程估值;将离散的数据经推估插值计算转换为格网DEM数据．并根据其网格顶点推算显示网格单元的坡度和坡向．     

Health and well-being outcomes of women and children in Sub-Saharan Africa: Examining the role of formal schooling,literacy, and health knowledge

Health is related to individual educational attainment and literacy status; yet education and literacy do not guarantee health knowledge. Prior research studies health knowledge, formal schooling, and literacy as one entity, neglecting crucial differences. Using Demographic and Health Surveys from 27 sub-Saharan African countries, we examine these three pathways to gaining information, acknowledging each is distinct in target population, content, and delivery method, and uniquely contributes to health outcomes for women and children. Overall, all three pathways increase health outcomes, though health-specific knowledge could address the cultural and financial barriers that often come between women and formal schooling.     

The Intellectual Demands of the Intended Primary Science Curriculum in Korea and Singapore: An analysis based on revised Bloom's taxonomy

While there has been a remarkable worldwide convergence in the emphases of primary science curricula over the last four decades, the cognitive and knowledge demands that they make on learners have not been well-researched. Without knowing what these intellectual or epistemic requirements are when learning science in school, issues concerning curricular alignment and access to abstract disciplinary knowledge are also likely to occur. To highlight the value of such forms of analyses, we examine the intended primary science curricula from Korea and Singapore using revised Bloom's taxonomy, as well as describe some of their general features for teaching. The results contribute insights into the complexities of the science curriculum among two similar yet different educational systems that have performed well in international science achievement tests at primary levels.     

中国基础教育研究的国际影响审视：主题、价值表述与被引

基于对99篇研究中国基础教育的SSCI高被引论文的主题分布、对中国基础教育研究价值的表述以及被引用情况的分析,发现这些高被引论文通过凸显中国学生的优异成绩、揭示与他国教育存在的共性问题等方式吸引了国际学界关注,但对有中国特色教育实践的描述分析以及对中国基础教育独特研究价值的发掘尚有不足。相关成果对中国基础教育研究价值的建构方式需要实现从成绩到经验、从问题到方案、从数据到理论的转变,才能进一步提升中国教育研究的国际学术影响力。     

Learning With Dynamic Geometry Programs: Perspectives of Teachers and Learners

Abstract

In this exploratory phenomenological study, part of a larger mixed-design research project, the authors examined teacher and student roles in, and reactions to, a student-centered instructional geometry program using the Geometer's Sketchpad. Grade 7 students worked for 2 weeks in their regularly scheduled mathematics class on activities that allowed them to explain on-screen relationships among geometric shapes. A companion computer-based instructional tutorial was available as an accessible resource. The class sessions and specific dyads were observed, students surveyed, and teacher and selected students interviewed. Findings centered on 2 overarching themes: issues of power and learning. The teacher had difficulty relinquishing control of the learning environment even though she had agreed to do so. Students, however, liked their new freedom, worked hard, and expressed greater interest in the subject material.