Approximating Test Statistics Using Eigenvalue Block Averaging     

Njål Foldnes  Steffen Grønneberg 《Structural equation modeling》2018,25(1):101-114

We introduce and evaluate a new class of approximations to common test statistics in structural equation modeling. Such test statistics asymptotically follow the distribution of a weighted sum of i.i.d. chi-square variates, where the weights are eigenvalues of a certain matrix. The proposed eigenvalue block averaging (EBA) method involves creating blocks of these eigenvalues and replacing them within each block with the block average. The Satorra–Bentler scaling procedure is a special case of this framework, using one single block. The proposed procedure applies also to difference testing among nested models. We investigate the EBA procedure both theoretically in the asymptotic case, and with simulation studies for the finite-sample case, under both maximum likelihood and diagonally weighted least squares estimation. Comparison is made with 3 established approximations: Satorra–Bentler, the scaled and shifted, and the scaled F tests.  相似文献   

Innovation paths and the innovation performance of low-technology firms—An empirical analysis of German industry     

Eva Kirner  Steffen Kinkel  Angela Jaeger 《Research Policy》2009,38(3):447-458

This paper analyses innovation paths and the innovation performance of low-technology firms in comparison to medium- and high-technology firms. Firstly, it shows that low-, medium- and high-technology sectors consist of a considerable mix of low-, medium- and high-technology firms. Thus, it is necessary to look at the firm level when analysing how innovation patterns differ depending on the level of R&D intensity. Secondly, the product and process innovation performance of low-technology firms in German industry is analysed based on data from 1663 firms in the German Manufacturing Survey 2006, applying a set of both product and process related innovation output indicators. The empirical results show that low-technology manufacturing firms lag behind their medium- and high-tech counterparts regarding their product and service innovation performance, to a large degree on purely definitional grounds, but that they seem to perform equally well and in some respects even better at process innovation.  相似文献   

Three-dimensional CoM energetics,pelvis and lower limbs joint kinematics of uphill treadmill running at high speed     

Masamichi Okudaira  Steffen Willwacher  Seita Kuki  Kaito Yamada  Takuya Yoshida  Satoru Tanigawa 《Journal of sports sciences》2020,38(5):518-527

ABSTRACT

The purpose of this study was to investigate the effects of slope on three-dimensional running kinematics at high speed. Thirteen male sprinters ran at high speed (7.5 m/s) on a motorised treadmill in each a level and a 5.0% slope condition. Three-dimensional motion analysis was conducted to compare centre of mass (CoM) energetics, pelvis segment and lower limb joints kinematics. We found that contact time was not affected by the slope, whereas flight time and step length were significantly shorter in uphill compared to level running. Uphill running reduced negative CoM work and increased positive CoM work compared to level running. Ankle, knee and hip joints were more flexed at initial ground contact, but only the knee was more extended at the end of stance in uphill compared to level running. Additionally, the hip joint was more abducted, and the free leg side of the pelvis was more elevated at the end of stance in uphill running. Our results demonstrate that joint motion must be developed from a more flexed/adducted position at initial contact through a greater range of motion compared to level running in order to meet the greater positive CoM work requirements in uphill running at high speed.  相似文献   

An Attachment Model of University Connectedness     

Steffen Wilson  Jonathan Gore 《Journal of Experimental Education》2013,81(2):178-198

Students with high levels of connectedness to the university have been found to be more likely to complete their college degree than are students with low levels of university connectedness. This study examined the role of parental and peer attachment as distal predictors of school connectedness. As predicted, it was found that attachment style to parents predicted attachment style to peers. An avoidant attachment style to peers predicted negative perceptions of peer support and support services. An anxious attachment style to peers predicted negative perceptions of faculty support. Perceptions of peer support, support services, and faculty support then predicted feelings of connectedness to the university. Classroom comfort also predicted university connectedness, although it was not found to be related to attachment style to parents or peers. Implications for college students and college/university administrators are discussed.  相似文献   

From the open road to the high seas? Piracy,damnation and resistance in academic consumption of publishing     

Armin Beverungen  Steffen Böhm 《普罗米修斯》2013,31(3):241-247

Armin Beverungen conducts research on how universities retain their charitable status in a market environment, and on the teaching of ethics in business schools. Steffen Böhm has a particular interest in the economics and management of sustainability. He has also founded an open access journal and an open access press, MayFlyBooks. Christopher Land works on artists and the management of their creativity.  相似文献   

Evaluating an Automatically Scorable, Open-Ended Response Type for Measuring Mathematical Reasoning in Computer-Adaptive Tests     

Randy Elliot Bennett  Manfred Steffen  Mark Kevin Singley  Mary Morley  Daniel Jacquemin 《Journal of Educational Measurement》1997,34(2):162-176

The first generation of computer-based tests depends largely on multiple-choice items and constructed-response questions that can be scored through literal matches with a key. This study evaluated scoring accuracy and item functioning for an open-ended response type where correct answers, posed as mathematical expressions, can take many different surface forms. Items were administered to 1,864 participants in field trials of a new admissions test for quantitatively oriented graduate programs. Results showed automatic scoring to approximate the accuracy of multiple-choice scanning, with all processing errors stemming from examinees improperly entering responses. In addition, the items functioned similarly in difficulty, item-total relations, and male-female performance differences to other response types being considered for the measure.  相似文献   

The role of socioeconomic background and prior achievement for students’ perception of teacher support     

Cansu Atlay  Nicole Tieben  Benjamin Fauth  Steffen Hillmert 《British Journal of Sociology of Education》2019,40(7):970-991

Abstract

Building on the sociological work by Lareau, this study examined the association between students’ socioeconomic background, prior achievement and the perception of teacher support within the classroom. We expected that students from higher socioeconomic backgrounds would be more critical about the support they receive in the classroom and rate their teachers more negatively, while those with higher prior achievement would perceive teacher support more positively. Multilevel models confirmed that there is a negative association between wealth and students’ perception of two dimensions of teacher support, and a negative association between parental educational attainment and one dimension of teacher support. Our findings were in line with the ‘sense of entitlement’ theory by Lareau. Having higher prior achievement was associated with a more positive perception of teacher support, but did not seem to interact with socioeconomic background.  相似文献   

Going Beyond Convergence in Bayesian Estimation: Why Precision Matters Too and How to Assess It     

Steffen Zitzmann  Martin Hecht 《Structural equation modeling》2019,26(4):646-661

Most of the software that is available to implement Bayesian approaches uses Markov chain Monte Carlo (MCMC) methods. It is our impression that many researchers are primarily concerned with convergence as assessed by the Potential Scale Reduction (PSR) and that other aspects of MCMC are largely ignored. In this article, we argue that the precision with which the Bayesian estimates are approximated by summary statistics for the MCMC chain is essential to ensure good statistical properties. We discuss the Effective Sample Size (ESS), which indicates how well an estimate is approximated, and present evidence from two simulation studies and an example from organizational research to support our claim that researchers should be concerned not only with convergence but also with precision, particularly when a multilevel model is estimated. In addition, we demonstrate how Mplus can be modified so that users can control the ESS, and we conclude with recommendations.  相似文献   

Differentiation and social selectivity in German higher education     

Steffen Schindler  David Reimer 《Higher Education》2011,61(3):261-275

In this paper we investigate social selectivity in access to higher education in Germany and, unlike most previous studies, explicitly devote attention to semi-tertiary institutions such as the so-called universities of cooperative education. Drawing on rational choice models of educational decisions we seek to understand which factors influence upper secondary graduates from different social backgrounds in their choices of diverse tertiary institutions in Germany. We find that scholastic performance, expected job security, study duration, monetary costs and preferences for study content considerably contribute to the creation of socially selective choice patterns of post-secondary careers. The characteristics of semi-tertiary institutions—such as universities of cooperative education that combine firm-based training with tertiary education—constitute a potential alternative that could reduce inequities in access to higher learning.  相似文献   

Open wedge re-correction high tibial osteotomy in an elderly patient with a varus angulated non-united dome-shaped high tibial osteotomy     

Steffen Schröter  Lukas Konstantinidis  Tobias M. Kraus  Fabian Stuby  Ulrich Stöckle  Thomas Freude 《Journal of Zhejiang University. Science. B》2013,14(11):1054-1058

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