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对于农业研究中多变量线性模型参数的估计,以往常采用经典统计方法。随着计算机技术的进步,贝叶斯统计方法在科学研究的各个领域迅速发展。文章利用贝叶斯统计方法对农业研究中的多变量模型进行参数估计,并与经典统计方法进行比较,验证了贝叶斯方法的有效性。该方法可为农业研究中多变量模型参数的估计提供新的途径和手段。 相似文献
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对半参数回归模型的研究是近年来统计研究的热点之一,它结合线性回归模型和非参数回归模型,吸收了各自的优点,因此不论是在理论研究上还是实际应用中都具有重要意义.文章总结了国内学者对半参数回归模型研究的贡献,理清了对该模型的理论研究演进的方向和脉络. 相似文献
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Maria Pampaka Graeme Hutcheson Julian Williams 《International Journal of Research & Method in Education》2016,39(1):19-37
Missing data is endemic in much educational research. However, practices such as step-wise regression common in the educational research literature have been shown to be dangerous when significant data are missing, and multiple imputation (MI) is generally recommended by statisticians. In this paper, we provide a review of these advances and their implications for educational research. We illustrate the issues with an educational, longitudinal survey in which missing data was significant, but for which we were able to collect much of these missing data through subsequent data collection. We thus compare methods, that is, step-wise regression (basically ignoring the missing data) and MI models, with the model from the actual enhanced sample. The value of MI is discussed and the risks involved in ignoring missing data are considered. Implications for research practice are discussed. 相似文献
4.
针对各学科领域中常遇到的多元线性回归问题,在简单介绍回归分析基本理论的基础上,结合一具体实例,详细介绍了基于回归算法编写MATLAB程序、利用MATLAB预定义函数以及二者相结合解决多元线性回归问题的方法。方法简单实用,其中基于算法编程、利用预定义函数及二者结合解决问题的方法不仅是解决多元线性回归问题的方法,也是利用MATLAB解决各学科领域中一般性数学问题的基本方法。 相似文献
5.
Does High School Matter? An Analysis of Three Methods of Predicting First-Year Grades 总被引：2，自引：0，他引：2
This research evaluated the usefulness of 3 approaches for predicting college grades: (a) traditional regression models, (b) high-school-effects models, and (c) hierarchical linear models. Results of an analysis of the records of 8,764 freshmen at a major research university revealed that both the high-school-effects model and the hierarchical linear model were more accurate predictors of freshman GPA than was the traditional model, particularly for lower ability students. Counter to expectations, the hierarchical linear model was not more accurate than the high school effects model. 相似文献
6.
George E. Counts 《Journal of Experimental Education》2013,81(3):24-27
The purpose of this report is to describe a process for creating unique multiple linear regression problems for each student. Three formulas were utilized to define intercorrelations between variables. A computer program was written based upon these mathematical relationships. To test the power of the program to “select” a random sample from variables with defined interrelationships, eleven examples were tested. On 33 sample correlation coefficients the expected number of significant correlations, 1.65, was larger than the number observed, 1. No difficulty is expected in preparing such problems for each student in a statistics or a research methods course, where professors may find problems of this type to be helpful. 相似文献
7.
Factor score regression has recently received growing interest as an alternative for structural equation modeling. However, many applications are left without guidance because of the focus on normally distributed outcomes in the literature. We perform a simulation study to examine how a selection of factor scoring methods compare when estimating regression coefficients in generalized linear factor score regression. The current study evaluates the regression method and the correlation-preserving method as well as two sum score methods in ordinary, logistic, and Poisson factor score regression. Our results show that scoring method performance can differ notably across the considered regression models. In addition, the results indicate that the choice of scoring method can substantially influence research conclusions. The regression method generally performs the best in terms of coefficient and standard error bias, accuracy, and empirical Type I error rates. Moreover, the regression method and the correlation-preserving method mostly outperform the sum score methods. 相似文献
8.
概率统计在社会的各个领域都有着广泛的应用,尤其是回归模型。对回归模型的预测与控制问题进行了研究。首先介绍了回归模型以及回归模型的预测与控制方法,然后分析了回归模型预测的步骤,最后以企业实例为基础,分别对一元回归模型的预测、二元回归模型的预测进行了分析。 相似文献
9.
This research considers the mathematical relationship between concentration of Chla and seven environmental factors, i.e. Lake water temperature (T), Secci-depth (SD), pH, DO, CODMn, Total Nitrogen (TN), Total Phosphorus (TP). Stepwise linear regression of 1997 to 1999 monitoring data at each sampling point of Qiandaohu Lake yielded the multi-variate regression models presented in this paper. The concentration of Chla as simulation for the year 2000 by the regression model was similar to the observed value. The suggested mathematical relationship could be used to predict changes in the lakewater environment at any point in time. The results showed that SD, TP and pH were the most significant factors affecting Chla concentration. 相似文献
10.
This research considers the mathematical relationship between concentration of Chla and seven environmental factors, i.e. Lake water temperature (T), Secci-depth (SD), pH, DO, CODMn, Total Nitrogen (TN), Total Phosphorus (TP).Stepwise linear regression of 1997 to 1999 monitoring data at each sampling point of Qiandaohu Lake yielded the multivariate regression models presented in this paper. The concentration of Chla as simulation for the year 2000 by the regression model was similar to the observed value. The suggested mathematical relationship could be used to predict changes in the lakewater environment at any point in time. The results showed that SD, TP and pH were the most significant factors affecting Chla concentration. 相似文献
11.
核磁共振找水仪采集信号的特征参数准确度对地下水的研究有很重要的意义．特征参数提取是否精确直接影响了反演解释含水层位置、含水量、以及孔隙度等水文地质信息．针对特征参数的多种提取方法,本文主要围绕线性拟合、非线性拟合和自相关拟合三种数据拟合方法进行对比,找出不同信噪比下最适合的特征参数提取方法．野外实测数据和反演结果也验证了方法的有效性． 相似文献
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Comparing the Effectiveness of Self‐Paced and Collaborative Frame‐of‐Reference Training on Rater Accuracy in a Large‐Scale Writing Assessment 
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下载免费PDF全文 Kevin R. Raczynski Allan S. Cohen George Engelhard Jr. Zhenqiu Lu 《Journal of Educational Measurement》2015,52(3):301-318
There is a large body of research on the effectiveness of rater training methods in the industrial and organizational psychology literature. Less has been reported in the measurement literature on large‐scale writing assessments. This study compared the effectiveness of two widely used rater training methods—self‐paced and collaborative frame‐of‐reference training—in the context of a large‐scale writing assessment. Sixty‐six raters were randomly assigned to the training methods. After training, all raters scored the same 50 representative essays prescored by a group of expert raters. A series of generalized linear mixed models were then fitted to the rating data. Results suggested that the self‐paced method was equivalent in effectiveness to the more time‐intensive and expensive collaborative method. Implications for large‐scale writing assessments and suggestions for further research are discussed. 相似文献
14.
为了解回归分析在体育科研中存在问题,探寻规避对策,采用文献资料法,专家访谈法,调查分析法等研究方法,在查阅近年来国内13种体育核心期刊论文的基础上,探讨了回归分析在体育科研应用中容易出现的模型检验、样本容量、逐步回归、虚拟变量等问题,进行一一诊断分析,并提出正确的处理方法,改善其应用效果,以期为进一步开展这方面研究,正确的运用回归分析提供科学参考。 相似文献
15.
张姣玲 《广东技术师范学院学报》2011,(9):31-33
提出了用人工蜂群算法解决多元线性回归问题.通过计算机仿真测试,表明人工蜂群算法在多元线性回归分析的参数估计问题中是有效的、实用的. 相似文献
16.
对外汉语词汇教学研究述评 总被引：1，自引：1，他引：0
文章对近年来对外汉语词汇教学内容和教学方法进行了分析,考察了语言学理论对对外汉语词汇教学的影响和当前对外汉语词汇教学研究中存在的问题,以期为进一步拓展研究空间提供借鉴。 相似文献
17.
Previous research suggests that the diagnosis of a comorbid learning disability is dependent on the method used for making the LD diagnosis. This study investigated that proposition by studying the effects of using three approaches to the assessment of learning disabilities in a sample of 177 six- to thirteen-year-old boys referred to outpatient mental health clinics for behavior problems. The use of these three procedures to diagnose comorbid learning problems produced significantly different results. All methods identified significant numbers of children in the clinical population as learning disabled; however, each method identified children with differing characteristics. Consistent with predictions from measurement theory, the commonly used simple standard score discrepancy method was more likely to identify children with above-average IQs as learning disabled, whereas a regression approach identified learning disabilities more consistently across the ability range. These results were interpreted as supporting the use of regression approaches to diagnose co-occurring learning disabilities, as that method is less likely to be biased by the child's intelligence test score. The implications of the use of each method in research investigations is also discussed. 相似文献
18.
Gerald W. McLaughlin James R. Montgomery Beatrice T. Mahan 《Research in higher education》1979,11(1):23-35
Factors which comprise the bases for salary increases and adjustments at major research universities have long been topics of conversation and supposition. Based on responses from over 12,000 faculty members, this paper reviews, by faculty rank, items which are likely to contribute to salary and suggests that faculty members can follow certain strategies which are more likely than others to bring a financial reward. Research procedures employed include linear models and multiple regression. 相似文献
19.
非参数回归模型的模型检验 总被引：1，自引：1，他引：0
在此考虑非参数回归模型的模型检验问题.基于Plug-in经验似然方法,构造经验似然比检验统计量.证明其满足Wilks’现象,而得到了一定显著性水平的拒绝域.最后通过数据模拟,讨论了其检验功效. 相似文献
20.
本文以河南省痢疾数据为例,通过大量直观的图表与统计分析手段相结合的方式,分析了痢疾的时空发病特征,并得出了痢疾的时空发病特征是有气象因素的时空分布特点所决定的结论,并进行相关分析得到了影响痢疾发病的主要影响因素.对传统的疾病估计预测方法进行总结,进而提出了趋势分段法并归纳了常见流行病的发展趋势阶段及相应处理方法,以郑州为例证实了趋势分段法相比传统方法具有一定优势.对于各地市数据,使用面板回归方法分析其共性之处,并综合讨论了以上模型的应用. 相似文献