共查询到20条相似文献，搜索用时 421 毫秒
1.
Tenko Raykov 《Structural equation modeling》2013,20(5):750-756
It is shown that the maximum likelihood estimator of the widely used omega coefficient for reliability of multicomponent measuring instruments converges almost surely to the population reliability coefficient for normal congeneric measures with uncorrelated errors as sample size increases indefinitely. This strong consistency implies convergence in probability (consistency) as well as in distribution for the omega estimator. Strong consistency is also demonstrated for the maximal reliability estimator associated with the optimal linear combination of the instrument components. The findings of this note add (i) to the recommendation to use in the general normality case the omega estimator in empirical research, (ii) to the critical literature on the popular coefficient alpha then, and (iii) to the literature on the properties of the optimal linear combination of observed measures and the maximal reliability estimator. 相似文献
2.
夏卫锋 《南阳师范学院学报》2005,4(3):13-14
主要讨论了几乎处处收敛与依概率收敛，完全收敛与几乎处处收敛的关系．给出了由依概率收敛推出几乎处处收敛的条件和由几乎处处收敛推出完全收敛的条件，从而比较完全地说明了随机变量序列的各种收敛性之间的关系． 相似文献
3.
{Xni}是行独立的B值随机元阵列，在适当的条件下，证明了1/n^1/p∑^ni=1XniL收敛于零，完全收敛于零，几乎处处收敛于零，依概率收敛于零是等阶的。 相似文献
4.
研究了误差为AANA序列时非参数回归模型未知函数g（·）估计量的相合性问题,而AANA序列比NA序列要弱．在-般的条件下,利用C,不等式、Jensen不等式、AANA序列的极大值不等式以及权函数的-些性质,给出了非参数回归模型未知函数g（·）估计量的P-阶平均相合性和-致P-阶平均相合性,推广了相关文献已获得的部分结果． 相似文献
5.
Evaluation of Dimensionality in the Assessment of Internal Consistency Reliability: Coefficient Alpha and Omega Coefficients 
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下载免费PDF全文 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. 相似文献
6.
The main purpose of this study is to develop a valid and reliable instrument for measuring the attitudes toward science class of fourth‐ and fifth‐grade students in an Asian school culture. Specifically, the development focused on three science attitude constructs—science enjoyment, science confidence, and importance of science as related to science class experiences. A total of 265 elementary school students in Taiwan responded to the instrument developed. Data analysis indicated that the instrument exhibited satisfactory validity and reliability with the Taiwan population used. The Cronbach’s alpha coefficient was 0.93 for the entire instrument indicating a satisfactory level of internal consistency. However, both principal component analysis and parallel analysis showed that the three attitude scales were not unique and should be combined and used as a general “attitudes toward science class” scale. The analysis also showed that there were no gender or grade‐level differences in students’ overall attitudes toward science class. 相似文献
7.
主要讨论了Banach代数中鞅变换的收敛性,指出在一类条件下,鞅变换是依范数收敛及几乎处处收敛的. 相似文献
8.
对Kummer判别法的讨论 总被引：1，自引：0，他引：1
胡晶地 《株洲师范高等专科学校学报》2003,8(5):54-56
比式判别法和根式判别法是对正项级数收敛性进行判别的两种广用的方法．但如果正项级数的通项收敛于零的速度较某一几何级数的通项收敛于零的速度慢，这两种方法则无用．先讨论一个判别范围更广的Kummer判别法，并将传统的几种方法作为此判别法的一种特例给出． 相似文献
9.
王平华 《洛阳师范学院学报》2003,(2)
对概率型Sz偄ｓｚ算子Ｓｎ(f,x)在 ( 0 ,+∞ )上收敛于 [f(x+ ) +f(x-) ]/2的收敛速度进行了研究 ,并利用概率论的方法 ,对Guo和Khan关于Sn(f,x)的收敛速度的估计作进一步的改进 ,得到更精确的系数估计 相似文献
10.
Laura Trinchera Nicolas Marie George A. Marcoulides 《Structural equation modeling》2018,25(6):876-887
Scales are important tools for obtaining quantitative measures of theoretical constructs. Once a set of measures to be used in a scale is selected, reliability is commonly examined in order to assess their measurement quality. To date, Cronbach’s coefficient alpha is the most commonly reported index of measurement quality for assessing scale reliability. In this paper, an asymptotic distribution of the natural estimator of coefficient alpha is derived. A new interval estimate and a statistical test on the significance of the sample estimate of the coefficient are also presented. The proposed approach is compared to four popular methods commonly used to compute confidence intervals (CI) for alpha using a Monte Carlo simulation study. An R function for implementing the proposed CI approach is also provided. 相似文献
11.
Klaas Sijtsma 《Educational Measurement》2015,34(4):10-13
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. 相似文献
12.
随机变量序列依概率收敛是概率论中一种较重要的收敛形式,本文分析了依概率收敛认识的几个误区,并结合反例给予了说明。 相似文献
13.
在一般拓扑空间中,以远域为工具引入和研究网的S-收敛性、θ-收敛性、δ-收敛性等概念,并利用这些概念给出半连续映射、弱连续映射和几乎连续映射的一些等价条件. 相似文献
14.
主要研究了模糊随机变量的收敛性，总结出了几乎一致收敛和依均值收敛的概念，并讨论了各收敛的数学性质和收敛之间的关系． 相似文献
15.
Wording effect refers to the systematic method variance caused by positive and negative item wordings on a self-report measure. This Monte Carlo simulation study investigated the impact of ignoring wording effect on the reliability and validity estimates of a self-report measure. Four factors were considered in the simulation design: (a) the number of positively and negatively worded items, (b) the loadings on the trait and the wording effect factors, (c) sample size, and (d) the magnitude of population validity coefficient. The findings suggest that the unidimensional model that ignores the negative wording effect would underestimate the composite reliability and criterion-related validity, but overestimate the homogeneity coefficient. The magnitude of relative bias of the composite reliability was generally small and acceptable, whereas the relative bias for the homogeneity coefficient and criterion-related validity coefficient was negatively correlated with the strength of the general trait factor. 相似文献
16.
Michael B. Miller 《Structural equation modeling》2013,20(3):255-273
This article is a pedagogical piece on coefficient alpha (α) and its uses. The classical approach to test reliability is explained. Test‐retest, alternative‐forms, and internal‐consistency methods of approximating test reliability are described, equations are derived for each method, and α is shown to be a lower‐bound internal‐consistency approximation to test reliability. Emphasis is placed on the effects of violations of model assumptions on reliability estimation. The classical models are conceptualized as structural equation models and are displayed in path diagrams. Special emphasis is placed on the failure of α to meet certain basic criteria as an index of test homogeneity. 相似文献
17.
通过反例说明了一致收敛是和函数分析性质的充分而非必要条件,由此看出在数学分析教学中合理恰当地运用反例会收到很好的教学效果;同时给出和函数连续性的三种等价形式,而且在使用时,各有好处,最后给出判断一个函数项级数非一致收敛的判别法. 相似文献
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19.
王龙 《黄冈师范学院学报》2013,33(3):1-4
应用不确定理论在已知平均收敛能推出依测度收敛和依分布收敛的基础上,列举了一个例子,并通过这个例子来讨论它的四个收敛性,即研究它是否几乎处处收敛、平均收敛、依测度收敛和依分布收敛. 相似文献
20.
从不确定变量的公理化定义和不确定变量的基本极限性质出发,借助一般的极限定理思想,在不确定变量的双重极限理论基础上,进一步研究了不确定变量的双重收敛性。讨论了不确定变量几乎处处收敛,几乎一致收敛与依测度收敛之间的嵌套定理。 相似文献