Advanced Nonlinear Latent Variable Modeling: Distribution Analytic LMS and QML Estimators of Interaction and Quadratic Effects     

Augustin Kelava  Christina S. Werner  Karin Schermelleh-Engel  Helfried Moosbrugger  Dieter Zapf  Yue Ma 《Structural equation modeling》2013,20(3):465-491

Interaction and quadratic effects in latent variable models have to date only rarely been tested in practice. Traditional product indicator approaches need to create product indicators (e.g., x ₁ ², x ₁ x ₄) to serve as indicators of each nonlinear latent construct. These approaches require the use of complex nonlinear constraints and additional model specifications and do not directly address the nonnormal distribution of the product terms. In contrast, recently developed, easy-to-use distribution analytic approaches do not use product indicators, but rather directly model the nonlinear multivariate distribution of the measured indicators. This article outlines the theoretical properties of the distribution analytic Latent Moderated Structural Equations (LMS; Klein & Moosbrugger, 2000) and Quasi-Maximum Likelihood (QML; Klein & Muthén, 2007) estimators. It compares the properties of LMS and QML to those of the product indicator approaches. A small simulation study compares the two approaches and illustrates the advantages of the distribution analytic approaches as multicollinearity increases, particularly in complex models with multiple nonlinear terms. An empirical example from the field of work stress applies LMS and QML to a model with an interaction and 2 quadratic effects. Example syntax for the analyses with both approaches is provided.  相似文献   

Phonological Awareness and Rapid Automatized Naming as Longitudinal Predictors of Reading in Five Alphabetic Orthographies with Varying Degrees of Consistency     

Karin Landerl  H. Harald Freudenthaler  Moritz Heene  Peter F. De Jong  Alain Desrochers  George Manolitsis 《Scientific Studies of Reading》2013,17(3):220-234

ABSTRACT

Although phonological awareness (PA) and rapid automatized naming (RAN) are confirmed as early predictors of reading in a large number of orthographies, it is as yet unclear whether the predictive patterns are universal or language specific. This was examined in a longitudinal study across Grades 1 and 2 with 1,120 children acquiring one of five alphabetic orthographies with different degrees of orthographic complexity (English, French, German, Dutch, and Greek). Path analyses revealed that a universal model could not be confirmed. When we specified the best-fitting model separately for each language, RAN was a consistent predictor of reading fluency in all orthographies, whereas the association between PA and reading was complex and mostly interactive. We conclude that RAN taps into a language-universal cognitive mechanism that is involved in reading alphabetic orthographies (independent of complexity), whereas the PA–reading relationship depends on many factors like task characteristics, developmental status, and orthographic complexity.  相似文献   

Repeated Reading of Syllables Among Finnish-Speaking Children With Poor Reading Skills     

Sini Huemer  Mikko Aro  Karin Landerl  Heikki Lyytinen 《Scientific Studies of Reading》2013,17(4):317-340

The study evaluated the effect of repeated reading on reading speed among 36 Finnish-speaking poor readers in Grades 4 to 6. A switching replications design was applied: Group A (n = 20) received training first, and during this period Group B (n = 16) acted as a control group. After a midpoint test, the design was switched. The training material consisted of syllables, which were practiced during 10 training sessions for a total of 50 times. The reading speed of the trained syllables increased more during training than during the control period. During training, the reading speed of pseudowords containing the trained syllables improved significantly. This improvement was found both in a computer task and in a list-reading task, which had a lower congruency with the training method than the computer task. Finally, training did not induce changes in a control (text reading) task that assessed general reading speed.  相似文献   

How to persuade honors students to go the extra mile: creating a challenging learning environment     

Karin Scager  Sanne F. Akkerman  Albert Pilot  Theo Wubbels 《High Ability Studies》2013,24(2):115-134

Although universities aim to challenge high-ability students to develop their talents to the full, the question of how to create such challenges remains unanswered. In this study, we examined six different honors courses to discover which factors in the learning environment specifically designed for high-ability students challenged these students and determined how such challenges were established. Perceived challenges (factors and intensity) in the different courses were identified from focus group interviews with students. The interviews were guided by a storyline method which retrospectively discussed students’ experiences of course activities. In addition, course materials and audio-recorded classes were analyzed to describe how challenge was established. Results revealed three challenge factors: autonomy, complexity, and teacher expectations, similar to the ones found in a previous, single-case study. Results showed that the greatest challenge was experienced when the three factors were simultaneously experienced in the learning environment. These three challenge factors were manifested in various and sometimes very subtle ways through course design (e.g. open structure of assignments) and class interactions (e.g. particular ways of questioning).  相似文献   

Can digital information literacy among undergraduates be improved? Evidence from an experimental study     

Hannes Weber  Steffen Hillmert  Karin Julia Rott 《Teaching in Higher Education》2013,18(8):909-926

ABSTRACT

The Internet has become a pivotal source of information among university students. However, studies routinely show that many students lack digital information literacy skills (i.e. skills needed to find and evaluate information online). In this paper, we report results from an experimental study testing the effect of a workshop for third-year students of a German university. The workshop was designed to teach relevant information literacy skills in a computer lab. Afterwards, students were given academic search tasks and their search behavior was recorded with a tracking device. We find that, compared with the control group, workshop participants significantly increased their use of academic databases and cited more articles from scholarly journals. On the other hand, we find no effect on the relevance of the content students found online. Teaching digital information literacy is essential and feasible, but it is no panacea for increasing the academic quality of students’ work.  相似文献   

Influences on academics' approaches to development: voices from below     

Karin Crawford 《International Journal for Academic Development》2013,18(3):189-202

The purpose of this qualitative case study research was to explore faculty‐based academics' views on what influences their behaviours and attitudes towards their development. Informed by critical realist ontology, the data collection was carried out through narrative interviews with academics in two contrasting English universities. Findings, or areas for reflection, have emerged about the constraints and enablements academics perceive in respect of their professional development. In particular, themes such as: the significance of professional status; misaligned initiatives and priorities; the influence of supportive networks; and emergent personal, individual concerns have surfaced. The conclusion is drawn that the significance of agency raises the importance of responding to the ‘voices from below’.  相似文献   

Clinicians' opinions on the clinical relevance of anatomy education at Stellenbosch University     

Robyn Lunn-Collier  Jodie I. Layman-Lemphane  Karin J. Baatjes  Janine Correia 《Anatomical sciences education》2022,15(4):745-753

Anatomical science is a fundamental element of undergraduate medical education; thus, it is imperative that the course serves future medical professionals when entering clinical practice. However, anatomical education has faced challenges in recent years including decreased allocated time, increased class sizes and over-stretched staff. Technological advancements in anatomical education may provide relief to these issues. Therefore, exploring clinicians' perspective on the clinical relevance and efficacy of anatomical education, within an African context, can inform its future. This study used a qualitative research approach within an interpretive paradigm. Eight semi-structured one-on-one interviews were conducted with clinicians associated with Stellenbosch University and Tygerberg Hospital. Thematic analysis was employed to analyze the data, creating themes and codes. Trust worthiness of the data was ensured through peer debriefing and member checking. Results reveal that clinicians find clinically relevant anatomy valuable to students. However, some feel that this is not delivered effectively at present. Clinicians see potential for the incorporation of clinical technologies into anatomical pedagogy. Although clinicians are hopeful for new technological developments in anatomical education, concerns were reported about its autonomous nature. This study concludes that although clinically relevant anatomical education is beneficial to students, the time and the resources via which it is delivered should be considered. There is optimism for the future of anatomical education with the advancements of technologically based educational resources, however, new resources should be incorporated with planning and supervision.  相似文献   

University libraries as a model for the determination of the need for information specialists in knowledge industries? An exploratory analysis of the information sector in Austria     

Robert M. Hayes  Karin Karlics  Christian Schloegl 《Information processing & management》2013

In our paper we present an experimental study which investigated the possibility to project the need for information specialists serving knowledge workers in knowledge industries on the basis of an average university library serving their counterparts at a university. Information management functions, i.e. functions and processes related to information evaluation, acquisition, metadata creation, etc., performed in an average university library are the starting point of this investigation. The fundamental assumption is that these functions do not only occur in libraries but also in other contexts like, for instance, in knowledge industries. As a consequence, we try to estimate the need for information professionals in knowledge industries by means of quantitative methods from library and information science (Library Planning Model) and economics (input output analysis, occupational analysis). Our study confirms the validity of our assumption. Accordingly, the number of information specialists projected on the basis of university libraries is consistent with their actual number reported in national statistics. However, in order to attain a close fit, we had to revise the original research model by dismissing the split-up of information specialists into reader services and technical services staff.  相似文献   

ATP and phosphocreatine utilization in single human muscle fibres during the development of maximal power output at elevated muscle temperatures     

Stuart R. Gray  Karin Söderlund 《Journal of sports sciences》2013,31(7):701-707

Abstract

In this study, we examined the effect of muscle temperature (T _m) on adenosine triphosphate (ATP) and phosphocreatine utilization in single muscle fibres during the development of maximal power output in humans. Six male participants performed a 6-s maximal sprint on a friction-braked cycle ergometer under both normal (T _m = 34.3°C, s = 0.6) and elevated (T _m = 37.3°C, s = 0.2) muscle temperature conditions. During the elevated condition, muscle temperature of the legs was raised, passively, by hot water immersion followed by wrapping in electrically heated blankets. Muscle biopsies were taken from the vastus lateralis before and immediately after exercise. Freeze-dried single fibres were dissected, characterized according to myosin heavy chain composition, and analysed for ATP and phosphocreatine content. Single fibres were classified as: type I, IIA, IIAX25 (1 – 25% IIX isoform), IIAX50 (26 – 50% IIX), IIAX75 (51 – 75% IIX), or IIAX100 (76 – 100% IIX). Maximal power output and pedal rate were both greater (P < 0.05) during the elevated condition by 258 W (s = 110) and 22 rev · min^?1 (s = 6), respectively. In both conditions, phosphocreatine content decreased significantly in all fibre types, with a greater decrease during the elevated condition in type IIA fibres (P < 0.01). Adenosine triphosphate content was also reduced to a greater (P < 0.01) extent in type IIA fibres during the elevated condition. The results of the present study indicate that after passive elevation of muscle temperature, there was a greater decrease in ATP and phosphocreatine content in type IIA fibres than in the normal trial, which contributed to the higher maximal power output.  相似文献   

Do kinaesthetic tapes affect plantarflexor muscle performance?     

Robert Csapo  Malvina Herceg  Luis M. Alegre  Richard Crevenna  Karin Pieber 《Journal of sports sciences》2013,31(14):1513-1519

Abstract

This study aimed to examine the effects of application of kinaesthetic tapes on plantarflexor muscle performance. We hypothesised that taping of the triceps surae muscle would improve plantarflexor muscle strength and endurance with no significant effect on drop jump performance. Using a repeated-measures design, all performance measures were obtained in 24 volunteers on two separate occasions: without tapes and after application of kinaesthetic tapes. Performance tests included measurements of isometric plantarflexor muscle strength and the associated electromyographic activity of the gastrocnemius muscle, an isokinetic fatigue resistance test (30 contractions at 180° · s^?1) and assessments of drop jump performance. The taping-intervention was associated with an increase in gastrocnemius electromyographic activity. However, significant increases in isometric strength were only found at fully dorsiflexed ankle positions (+12% at ?20°). Strength gains were negatively correlated to baseline strength (r = ?.58). The intervention did not affect the results of the isokinetic fatigue and drop jump tests. The application of kinaesthetic tapes over the triceps surae muscle promotes an increase in isometric strength and gastrocnemius muscle activity. Our data suggest that these effects are joint-angle dependent and more prominent in weaker individuals. By contrast, the taping-intervention improves neither drop jump performance nor muscular endurance.  相似文献