Evaluating Model Fit With Ordered Categorical Data Within a Measurement Invariance Framework: A Comparison of Estimators

A paucity of research has compared estimation methods within a measurement invariance (MI) framework and determined if research conclusions using normal-theory maximum likelihood (ML) generalizes to the robust ML (MLR) and weighted least squares means and variance adjusted (WLSMV) estimators. Using ordered categorical data, this simulation study aimed to address these queries by investigating 342 conditions. When testing for metric and scalar invariance, Δχ² results revealed that Type I error rates varied across estimators (ML, MLR, and WLSMV) with symmetric and asymmetric data. The Δχ² power varied substantially based on the estimator selected, type of noninvariant indicator, number of noninvariant indicators, and sample size. Although some the changes in approximate fit indexes (ΔAFI) are relatively sample size independent, researchers who use the ΔAFI with WLSMV should use caution, as these statistics do not perform well with misspecified models. As a supplemental analysis, our results evaluate and suggest cutoff values based on previous research.     

Treatment Utilization on College Campuses: Who Seeks Help for What?

The purpose of this study was to develop a better understanding of why college students seek psychological treatment by examining indicators of psychological distress. A secondary goal was to assess the utility of screening for treatment need via a brief self‐report measure of distress. Two samples (1 clinical, 1 nonclinical; N= 8,380) were examined via logistic regression analyses to identify meaningful predictors of treatment‐seeking behavior. Clinical applications are discussed.     

聚醚砜中空纤维超滤膜的研制

本文以聚醚砜（PES）为膜材料,聚乙烯吡咯烷酮（PVP）、聚乙二醇（PEG）-400为添加剂,N,N-二甲基乙酰胺（DMAC）为溶剂,用非溶剂致相分离法制备了超滤膜——聚醚砜中空纤维超滤膜。通过正交试验法探索喷丝头距离水面的高度、凝固浴的温度、PES浓度、PEG-400浓度等因素对膜性能的影响,同时进一步研究了三个因素对成膜性能的影响规律,分析并确定了制备PES中空纤维超滤膜的最佳实验条件为：喷丝头距离水面的高度20cm,凝固浴温度318K-328K,PES浓度为18％。     

油田污水处理厂含油污泥处理研究

对目标污泥进行试验分析,获得最佳工艺条件后将含油污泥在经搅拌后静置分离,原油回收,泥水经机械脱水过滤。过滤后油泥利用氧化钙将除油后污泥在干燥反应器内发生的热化学反应,将细胞水在反应器内大部分蒸发,达到脱水、杀菌等目的。利用微波加热器将部分低温蒸汽加热至250℃以供再次强化干燥。经试验测定,经增钙干化后处理污泥含水率控制在35%以内。     

The Research Quarterly and Its Antecedents

Abstract

In this introductory article to the 50th Anniversary Issue, Roberta J. Park traces the efforts of professional physical education organizations, especially at the national level, to accommodate scholarly/research interests. She describes the forerunner of the Research Quarterly and the way in which efforts led to establishment of a research journal. Park tells the history of the Quarterly since its inception in 1930 and notes a number of concerns related to its operations and policies that have been periodically expressed over the past 50 years. Several of these issues have assumed increasing importance as a result of the knowledge explosion in the various subdisciplines in physical education, along with the problems associated with expanding our national organization and its ability to serve all of its interest groups.     

Calculating upper limb inertial parameters

Abstract

In the kinematic and kinetic analysis of human movement, an accurate assessment of the inertial properties of the body segments under investigation is often essential. Statistical and geometric models of the segments of the upper limb were examined to determine their ability to predict the moments of inertia of these segments. The cadaver data of Chandler et al. (1975) were used as the criteria with which computed values were compared. The regression equations of Hinrichs (1985) gave the most accurate results; the geometric models appeared to offer the greatest flexibility.     

Private Higher Education and Economic Development

In Western Europe, especially in Germany, private higher education is generally perceived as an alternative to public higher education for students from relatively affluent families; more broadly, there is a general perception that attending a private higher education institution is correlated to wealth. This perception is influenced by private higher education in the US, which is the world's most visible private system, but also probably the most atypical. In this article, we will analyse the relationship between private higher education attainment and the wealth of nations as reflected by their per capita GDP. We will try to relate the indicators in models that use cross-sectional transnational data as well as time series analysis for four contrasting countries (Chile, Germany, Romania, and the US). We will address two questions: (1) do wealthier nations have a higher percentage of enrolment in private higher education? and (2) does enrolment in private higher education grow with economic growth? Our analysis shows that a simple general relationship between enrolment in private higher education and the wealth of nations does not exist.     

“工学结合”下对医学高职高专院校康复治疗技术专业学生开设医疗体育课程的研究

本文通过医疗体育课程的教学,使学生既学到了医学教材以外的技能,丰富了医疗知识,提高了医疗技术水平,同时也锻炼了身体,增强了体质,改善了形体,调节了身心,它是融健身、健美、健心于一体的医疗性体育运动。     

Statistical Power of Randomization Tests Used with Multiple-Baseline Designs

Statistical power was estimated for 3 randomization tests used with multiple-baseline designs. In 1 test, participants were randomly assigned to baseline conditions; in the 2nd, intervention points were randomly assigned; and in the 3rd, the authors used both forms of random assignment. Power was studied for several series lengths (N = 10, 20, 30), several effect sizes (d = 0, 0.5, 1.0, 1.5, 2.0), and several levels of autocorrelation among the errors (p ₁ = 0, .1, .2, .3, .4, and .5). Power was found to be similar among the 3 tests. Power was low for effect sizes of 0.5 and 1.0 but was often adequate (> .80) for effect sizes of 1.5 and 2.0.     

A Note on Noncentrality Parameters for Contrast Tests in a One-Way Analysis of Variance

The noncentrality parameter for a contrast test in a one-way analysis of variance is based on the dot product of 2 vectors whose geometric meaning in a Euclidian space offers mnemonic hints about its constituents. Additionally, the noncentrality parameters for a set of orthogonal contrasts sum up to the noncentrality parameter for the omnibus F test. The author provides an example of Helmert contrasts to demonstrate the use of the noncentrality parameters in contrast tests.