Sensitivity of SEM Fit Indexes With Respect to Violations of Uncorrelated Errors     

Moritz Heene  Sven Hilbert  H. Harald Freudenthaler  Markus Bühner 《Structural equation modeling》2013,20(1):36-50

This simulation study investigated the sensitivity of commonly used cutoff values for global-model-fit indexes, with regard to different degrees of violations of the assumption of uncorrelated errors in confirmatory factor analysis. It is shown that the global-model-fit indexes fell short in identifying weak to strong model misspecifications under both different degrees of correlated error terms, and various simulation conditions. On the basis of an example misspecification search, it is argued that global model testing must be supplemented by this procedure. Implications for the use of structural equation modeling are discussed.  相似文献   

Learning in a game-based virtual environment: a comparative evaluation in higher education     

Igor Mayer  Harald Warmelink  Geertje Bekebrede 《European Journal of Engineering Education》2013,38(1):85-106

The authors define the requirements and a conceptual model for comparative evaluation research of simulation games and serious games (SGs) in a learning context. A first operationalisation of the model was used to comparatively evaluate a suite of 14 SGs on varying topics played between 2004 and 2009 in 13 institutes of higher education in the Netherlands. The questions in this research were: what is the perceived learning effectiveness of the games and what factors explain it? How can we comparatively evaluate games for learning? Data were gathered through pre- and post-game questionnaires among 1000 students, leading to 500 useful datasets and 230 complete datasets for analysis (factor analysis, scaling, t-test and correlation analysis) to give an explorative, structural model. The findings are discussed and a number of propositions for further research are formulated. The conclusion of the analysis is that the students’ motivation and attitudes towards game-based learning before the game, their actual enjoyment, their efforts during the game and the quality of the facilitator/teacher are most strongly correlated with their learning satisfaction. The degree to which the experiences during the game were translated back into the underlying theories significantly determines the students’ learning satisfaction. The quality of the virtual game environment did not matter so much. The authors reflect upon the general methodology used and offer suggestions for further research and development.  相似文献   

The filament forming reactions of vimentin tetramers studied in a serial-inlet microflow device by small angle x-ray scattering     

Oliva Saldanha  Martha E. Brennich  Manfred Burghammer  Harald Herrmann  Sarah K?ster 《Biomicrofluidics》2016,10(2)

The structural organization of metazoan cells and their shape are established through the coordinated interaction of a composite network consisting of three individual filament systems, collectively termed the cytoskeleton. Specifically, microtubules and actin filaments, which assemble from monomeric globular proteins, provide polar structures that serve motor proteins as tracks. In contrast, intermediate filaments (IFs) assemble from highly charged, extended coiled coils in a hierarchical assembly mechanism of lateral and longitudinal interaction steps into non-polar structures. IF proteins are expressed in a distinctly tissue-specific way and thereby serve to generate the precise plasticity of the respective cells and tissues. Accordingly, in the cell, numerous parameters such as pH and salt concentration are adjusted such that the generation of functional networks is ensured. Here, we transfer the problem for the mesenchymal IF protein vimentin to an in vitro setting and combine small angle x-ray scattering with microfluidics and finite element method simulations. Our approach is adapted to resolve the early assembly steps, which take place in the sub-second to second range. In particular, we reveal the influence of ion species and concentrations on the assembly. By tuning the flow rates and thus concentration profiles, we find a minimal critical salt concentration for the initiation of the assembly. Furthermore, our analysis of the surface sensitive Porod regime in the x-ray data reveals that the formation of first assembly intermediates, so-called unit length filaments, is not a one-step reaction but consists of distinct consecutive lateral association steps followed by radial compaction as well as smoothening of the surface of the full-width filament.  相似文献   

Arthrose     

Miriam Hucke  Harald Leiss  Klaus Machold 《Wiener klinische Wochenschrift Education》2016,11(1-4):11-22

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Evaluating instructional software: A review and critique of current methods   总被引：1，自引：0，他引：1  

Robert A. Reiser  Harald W. Keglemann 《Educational technology research and development : ETR & D》1994,42(3):63-69

The purpose of this paper is to discuss the key features of various methods that software evaluation organizations employ to evaluate instructional software. Who conducts the evaluations, the processes they use for doing so, and the software features they evaluate are among the topics that are discussed. Some of the problems associated with many of the evaluation methods are also described, as is an alternate method designed to overcome some of the identified problems. Special emphasis is placed on the role of students as participants in the evaluation process, and the benefits that may be derived from placing students in that role.  相似文献   

Overshadowing of environmental cues by an odor in toxicosis-based conditioning in rats     

Harald Taukulis  Shane St. George 《Learning & behavior》1982,10(3):288-292

It was demonstrated that an odor presented to rats in a distinctive environment can interfere with toxicosis-based conditioning to the environmental cues. Rats poisoned when they drank unflavored water in a black compartment odorized with oil of eucalyptus exhibited no suppression of water intake when they were subsequently tested in the same compartment minus the odor. In contrast, rats poisoned in the same compartment minus the odor later exhibited reduced water consumption in that environment. Oil of eucalyptus proved to be as effective an overshadowing stimulus as a taste cue (a 1.5% NaCl solution).  相似文献   

Two factors of expertise? Excellence and professionalism of environmental experts     

Harald A. Mieg 《High Ability Studies》2009,20(1):91-115

The aim of this article is to empirically clarify factors and conditions of expertise. In addition to the core concept of expertise as excellence, a second factor needs to be taken into account: professionalism, or professional engagement. This hypothesis was tested and confirmed using data obtained from a survey on Swiss environmental professionals (n = 3514). The empirical test was based on factor analyses (Study 1) and a structural equation model (Study 2). The expertise scale consisted of nine items for self‐assessed perceived expertise amongst professional peers (α = .78). Excellence turned out to be a logarithmic function of years of practice (Study 3). Professionalism prevailed in domains where standards for best practices still needed to be established (Study 4).  相似文献   

The Many Meanings of Social Pedagogy: pedagogy and social theory in Scandinavia     

Harald Jarning 《Scandinavian Journal of Educational Research》2013,57(3-4):413-431

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Disaster,civil society and education in China: A case study of an independent non-government organization working in the aftermath of the Wenchuan earthquake     

Trey Menefee  Bjorn Harald Nordtveit 《International Journal of Educational Development》2012

In May 2008 nearly 90,000 people died in the most powerful earthquake in modern Chinese history. Many were students killed in substandard schools, creating a sensitive disaster zone inside a nation whose civil society organizations are beginning to flourish. This paper examines the education earthquake relief program of an international NGO, and the institutional environment the organization worked in. We argue that the restricted environment prevented implementation of high-impact programs in the most deprived places, but that the NGO needed to use the institutional opening created by the earthquake to establish a presence as an agent in China's development.  相似文献   

Ascent into darkness: German Himalaya expeditions and the National Socialist quest for high-altitude flight     

Harald Hoebusch 《国际体育史杂志》2013,30(4):520-540

This paper, via a detailed investigation of the lives and careers of scientists Dr Hans Hartmann, Dr Ulrich Cameron Luft, and Dr Bruno Balke, explores the relationship between high-altitude physiology research conducted on several 1930s German Himalaya expeditions and the efforts of the (National Socialist) German Luftwaffe at achieving high-altitude flight.  相似文献