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1.
Timothy Norris 《Research in higher education》1991,32(4):433-448
In recent years, much concern has been expressed about the quality of instruction provided by foreign teaching assistants (TAs) in higher education. Critiques of the use of foreign TAs generally argue that they often impede the learning process because of language barriers. The present study examines the effect that nonnative English-speaking TAs had on student performance over five semesters at the University of Wisconsin-Madison. Multiple ordinary least squares regression is used to analyze the relationship between student grades and nonnative English-speaking TAs. Subsamples based on a TA's geographic region of origin and instructional area are also analyzed. In addition, course drop rates and the impact of TA training programs are examined to determine possible influence on the results. The results of the analysis consistently indicate slightlybetter performance in sections conducted by nonnative English-speaking TAs. 相似文献
2.
对回归模型进行参数估计时,常用的两种重要方法是普通最小二乘法和最大似然法。随着社会的发展,普通最小二乘法的不足之处日益显现,另一种新的参数估计方法——累积法的推广和运用,为我们提供了新的研究思路。本文通过对这三种参数估计方法进行分析与比较,得出了一些新的启示。 相似文献
3.
Most studies of persistence behavior use path analysis or ordinary least squares regression to estimate unknown coefficients. However, estimates produced by these techniques are biased if selectivity bias contaminates choices made by individuals in the data sample. We explain this problem, argue that it is present in data samples used in persistence studies, and discuss an alternative estimation technique that controls for it. The methodology and the differences in the interpretation of coefficient estimates are illustrated with a data sample of individual students at a single university. 相似文献
4.
在当今西方经济学至少是所谓的"高级"西方经济理论中,数学已经成为阐述理论内容的基本要素或者说是通用语言.线性回归模型是最常用的经济计量模型,用于研究风险、保险、资产组合等经济问题,也可以用作经济预测.本文研究了线性回归模型中的参数估计问题,运用最小二乘法进行参数估计的数学分析基础.最小二乘法只是使用了函数的稳定点而没有运用数学分析的极值理论里的第一充分条件和第二充分条件,本文讨论最小二乘法的估计参数方法和数学分析的极值理论的方法是等价的. 相似文献
5.
Regression techniques are used frequently to analyze the relationships between university activity variables and the needs for different categories of resources. The ordinary least squares method (LS) has the disadvantage of being very sensitive to outliers. As an alternative the least median of squares (LMS) technique is discussed, which can resist a large fraction of contaminated data. To demonstrate the advantages of LMS, the parameters of some regression equations, estimated some years ago by means of ordinary least squares, and describing the needs for nonacademic staff and operating funds in a university, will be reestimated by means of this robust regression technique. 相似文献
6.
《Economics of Education Review》1995,14(2):167-178
This paper examines teachers' union activity in large school districts in the eleven states without collective bargaining legislation. A supply and demand model of municipal labor markets was used to specify reduced form wage, employment, and expenditure equations. These equations were then estimated using ordinary least squares regression analysis to determine the impact of teachers' collective bargaining. The presence of a collective bargaining agreement had a statistically significant effect on wages and district expenditures. Average teachers' sa;ary in districts with collective bargaining agreement was 9.5% higher than average salary in districts without collective bargaining agreements. Similarly, average school district expenditure was 15.6% higher in districts with collective bargaining agreements. 相似文献
7.
Caregivers’ use of metacognitive language in child care centers: Prevalence and predictors 总被引：1，自引：0，他引：1
Kristen L. Frampton Michal Perlman Jennifer M. Jenkins 《Early childhood research quarterly》2009,24(3):248-262
Use of metacognitive language by child care center staff in classrooms that serve preschool-aged children was examined. Staff's use of mental-state talk, perspective-taking talk, and activity-relevant questioning with children were coded in a series of 20-s snapshots taken over the course of one full morning per classroom. A total of 3401 snapshots were observed for 393 teachers in 103 classrooms. Staff used mental-state talk in 22% of the snapshots, activity-relevant questions in 12%, and perspective-taking talk in 3%. Structural and process predictors of staff's metacognitive language were examined for full-time staff (n = 148 in 95 classrooms) using multilevel modeling and ordinary least squares regression. Caregiver positive interaction style predicted caregivers’ engagement in all three types of language. Caregiver punitive interaction style was also a positive predictor of caregivers’ talk about others’ perspectives. In general, structural characteristics of the classroom were not significant predictors of staff's language. However, the proportion of children receiving a child care subsidy in the center negatively predicted perspective-taking discourse. Results indicate the importance of caregiver relational style in providing a more discourse-rich child care context. 相似文献
8.
Research on faculty productivity fails to account for the hierarchical nature of the data. Faculty members within an academic discipline more closely resemble one another than faculty in other disciplines, resulting in dependent observations and thus inaccurate statistical results. Unlike ordinary least squares, multilevel modeling takes into account this grouping effect. This article analyzes the research productivity of 1,104 tenured/tenure-track faculty from the 1993 NSOPF survey to compare traditional regression models with a random coefficients model. The results indicate a large grouping effect on research productivity, and the statistical as well as the substantive results of the random coefficients model differ significantly from the regression approach. 相似文献
9.
Barbara K. Iverson Ernest T. Pascarella Patrick T. Terenzini 《Research in higher education》1984,21(2):123-136
Based on prior research conducted at residential colleges and universities, nonclassroom informal faculty-student contact appears to be an element of student socialization. This study extends this line of research to a commuter student population. The extent to which informal contact socializes students by influencing their educational aspiration level in a commuter setting is investigated using a longitudinal data collection with the student as unit of analysis. Ordinary least squares and two-stage least squares techniques are used to analyze the data. Significant interactions between informal faculty-student contact and race were found. White and nonwhite students were sbusequently analyzed separately. The ordinary least squares (OLS) multiple regression results suggest that informal contact makes a slight but significant contribution to the explanation of freshmen aspirations for whites, but not for nonwhites. The two-stage least squares (2SLS) analysis suggests that the assumption that contact influences aspiration may not be valid and, indeed, that aspiration level may cause students to seek to initiate informal contact with faculty. 相似文献
10.
In the presence of omitted variables or similar validity threats, regression estimates are biased. Unbiased estimates (the causal effects) can be obtained in large samples by fitting instead the Instrumental Variables Regression (IVR) model. The IVR model can be estimated using structural equation modeling (SEM) software or using Econometric estimators such as two-stage least squares (2SLS). We describe 2SLS using SEM terminology, and report a simulation study in which we generated data according to a regression model in the presence of omitted variables and fitted (a) a regression model using ordinary least squares, (b) an IVR model using maximum likelihood (ML) as implemented in SEM software, and (c) an IVR model using 2SLS. Coverage rates of the causal effect using regression methods are always unacceptably low (often 0). When using the IVR model, accurate coverage is obtained across all conditions when N = 500. Even when the IVR model is misspecified, better coverage than regression is generally obtained. Differences between 2SLS and ML are small and favor 2SLS in small samples (N ≤ 100). 相似文献
11.
Marvin A. Titus 《Research in higher education》2007,48(4):487-521
Most research in the area of higher education is plagued by the problem of endogeneity or self-selection bias. Unlike ordinary
least squares (OLS) regression, propensity score matching addresses the issue of self-selection bias and allows for a decomposition
of treatment effects on outcomes. Using panel data from a national survey of bachelor’s degree recipients, this approach is
illustrated via an analysis of the effect of receiving a master’s degree, in various program areas, on wage earning outcomes.
The results of this study reveal that substantial self-selection bias is undetected when using OLS regression techniques.
This article also shows that, unlike OLS regression, propensity score matching allows for estimates of the average treatment
effect, average treatment on the treated effect, and the average treatment on the untreated effect on student outcomes such
as wage earnings. 相似文献
12.
Steffen Wirth 《Teaching Statistics》2003,25(1):29-32
This article discusses the influence extreme observations can exert on linear correlation between variables. It shows that standard p‐values obtained according to ordinary least squares and median regression can be misleading. Bootstrapping can prevent underestimation of the standard error of the regression coefficient and therefore unmask the deceiving correlation. 相似文献
13.
This study extends the scope of research that examines the connection between physical attractiveness and student perception through a survey analysis. While other studies concentrate on physical attractiveness alone, we examined not only perceptions of attractiveness but its impact on students’ perception of knowledge, approachability and faculty selection in a hypothetical course. Using ordered logistic regression, logistic regression and ordinary least squares regression to examine the interaction between age, attractiveness, knowledge and approachability, our findings show that younger faculty members are perceived as more approachable and more attractive, while older faculty members are perceived as more knowledgeable. Faculty perceived as more attractive are also perceived to be more approachable. Further, we test the impact that these results have on faculty selection in a hypothetical course and find that students are more likely to select an attractive and approachable faculty member to take a course with, regardless of perceived knowledge of the faculty member. Overall, although the perception of beauty may be cursory, its results may not be when considering the primacy effect, role model effect and teaching effectiveness assessment. 相似文献
14.
Sarah A. Font 《Child development》2014,85(5):2074-2090
This study uses a national sample of 1,215 children, ages 6–17, who spent some time in formal kinship or nonrelative foster care to identify the effect of placement type on academic achievement, behavior, and health. Several identification strategies are used to reduce selection bias, including ordinary least squares, change score models, propensity score weighting, and instrumental variables regression. The results consistently estimate a negative effect of kin placements on reading scores, but kin placements appear to have no effect on child health, and findings on children's math and cognitive skills test scores and behavioral problems are mixed. Estimated declines in both academic achievement and behavioral problems are concentrated among children who are lower functioning at baseline. 相似文献
15.
Tyler W. Watts Greg J. Duncan Douglas H. Clements Julie Sarama 《Child development》2018,89(2):539-555
The current study estimated the causal links between preschool mathematics learning and late elementary school mathematics achievement using variation in treatment assignment to an early mathematics intervention as an instrument for preschool mathematics change. Estimates indicate (n = 410) that a standard deviation of intervention‐produced change at age 4 is associated with a 0.24‐SD gain in achievement in late elementary school. This impact is approximately half the size of the association produced by correlational models relating later achievement to preschool math change, and is approximately 35% smaller than the effect reported by highly controlled ordinary least squares (OLS) regression models (Claessens et al., 2009; Watts et al., 2014 ) using national data sets. Implications for developmental theory and practice are discussed. 相似文献
16.
This study describes three least squares models to control for rater effects in performance evaluation: ordinary least squares (OLS); weighted least squares (WLS); and ordinary least squares, subsequent to applying a logistic transformation to observed ratings (LOG-OLS). The models were applied to ratings obtained from four administrations of an oral examination required for certification in a medical specialty. For any single administration, there were 40 raters and approximately 115 candidates, and each candidate was rated by four raters. The results indicated that raters exhibited significant amounts of leniency error and that application of the least squares models would change the pass-fail status of approximately 7% to 9% of the candidates. Ratings adjusted by the models demonstrated higher reliability and correlated slightly higher than observed ratings with the scores on a written examination. 相似文献
17.
This study assessed whether previous findings linking early maternal employment to lower cognitive and behavioral skills among middle‐class and White children generalized to other groups. Using a representative sample of urban, low‐income, predominantly African American and Hispanic families (n = 444), ordinary least squares regression and propensity score matching models assessed links between maternal employment in the 2 years after childbearing and children’s functioning at age 7. Children whose mothers were employed early, particularly in their first 8 months, showed enhanced socioemotional functioning compared to peers whose mothers remained nonemployed. Protective associations emerged for both part‐time and full‐time employment, and were driven by African American children, with neutral effects for Hispanics. Informal home‐based child care also heightened positive links. 相似文献
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19.
We present a short, inquiry-based learning course on concepts and methods underlying ordinary least squares (OLS), least absolute deviation (LAD), and quantile regression (QR). Students investigate squared, absolute, and weighted absolute distance functions (metrics) as location measures. Using differential calculus and properties of convex functions, students discover the sample mean, median, and pth quantile by minimizing sums of distances. Students use these metrics to define loss functions for OLS, LAD, and QR, and explore methods to minimize them. We discuss classroom experiences over two semesters. Classroom activities, Maple worksheets, and R demonstration code are available at a companion website. 相似文献
20.
Most studies of parent–child bookreading have focused on mothers reading to their children. Though the role of fathers in children's lives is widely emphasized, we know almost nothing about father–child bookreading, particularly among low-income families. The present study was designed to examine how often low-income fathers report reading to their children and what the predictors and effects of paternal bookreading are. The fathers in this study were participants in the national evaluation of Early Head Start (EHS) and were recruited via mothers enrolled in the EHS study. Participating fathers were interviewed at home and their children's cognitive and language development were assessed using standardized measures from ages 2 to 5. Results demonstrated a wide variety in frequency of bookreading among fathers. Fathers were more likely to read to their children frequently if they spoke English at home, if they had a high school education, and if their children had better language skills. Fathers’ bookreading predicted children's cognitive outcome. Paternal bookreading did predict children's language outcomes but only for children whose fathers had at least a high school education. 相似文献