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Augustin Merta 《Information processing & management》1978,14(6):465-467
Implication of national and supranational information industry on modelling nationwide networks of STI systems. Decentralized preparation and collection of formalized input bibliographic and/or factual data, centralized world-wide processing of both kinds of data bases and nationally decentralized output information services, as the most significant trends in the field of STI. The new role of secondary processor of special libraries and STI bureaus as the regional distributing centers of STI. The informational revolution as the parallel phenomenon of the scientific technical revolution. Problems of overcoming the national languages barriers. The debt of applied linguistics in introducing the machine readable primary texts, automated extracting, indexing and translating. On-line dialogue STI systems, the real information revolution. The necessary internationalization of STI systems. The gate-keepers role of future information scientist or engineer. The experiences of Czechoslovakia in using the sets of magnetic tape services. 相似文献
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In this article, we propose a nonlinear dynamic latent class structural equation modeling (NDLC-SEM). It can be used to examine intra-individual processes of observed or latent variables. These processes are decomposed into parts which include individual- and time-specific components. Unobserved heterogeneity of the intra-individual processes are modeled via a latent Markov process that can be predicted by individual- and time-specific variables as random effects. We discuss examples of sub-models which are special cases of the more general NDLC-SEM framework. Furthermore, we provide empirical examples and illustrate how to estimate this model in a Bayesian framework. Finally, we discuss essential properties of the proposed framework, give recommendations for applications, and highlight some general problems in the estimation of parameters in comprehensive frameworks for intensive longitudinal data. 相似文献
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Axel Mayer Nora Umbach Barbara Flunger Augustin Kelava 《Structural equation modeling》2017,24(4):556-570
In this article, we present an approach for comprehensive analysis of the effectiveness of interventions based on nonlinear structural equation mixture models (NSEMM). We provide definitions of average and conditional effects and show how they can be computed. We extend the traditional moderated regression approach to include latent continous and discrete (mixture) variables as well as their higher order interactions, quadratic or more general nonlinear relationships. This new approach can be considered a combination of the recently proposed EffectLiteR approach and the NSEMM approach. A key advantage of this synthesis is that it gives applied researchers the opportunity to gain greater insight into the effectiveness of the intervention. For example, it makes it possible to consider structural equation models for situations where the treatment is noneffective for extreme values of a latent covariate but is effective for medium values, as we illustrate using an example from the educational sciences. 相似文献
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Daniel Leyhr Johannes Raabe Florian Schultz Augustin Kelava Oliver Höner 《Journal of sports sciences》2020,38(11-12):1342-1351
ABSTRACT Considering the scarce empirical evidence regarding talent predictors in female youth soccer, the present study aimed to investigate the long-term prognostic validity of elite female soccer players’ adolescent motor performance for future success in adulthood. Additionally, the three-year development of highly talented girls’ motor performance and the predictive value of this motor development for reaching a professional adult performance level (APL) was analysed. Overall, N = 737 female players participated in nationwide motor diagnostics (sprinting, agility, dribbling, ball control, shooting) within the German Soccer Association’s talent identification and development programme at least twice between the age groups Under-12 (U12) and U15. Based on their APL at least four years later, participants were assigned to a professional (first German division, 6.2%) or non-professional group (lower divisions, 93.8%). Multilevel regression analyses revealed a general prognostic relevance for the investigated parameters with respect to players’ APL. In addition, there was a non-linear improvement in participants’ motor performance across all variables from U12 to U15. However, non-significant interactions between APL and these improvements indicate motor performance development itself cannot adequately predict players’ future success in adulthood. Findings provide insightful information that can help coaches foster optimal support for young female soccer players’ development. 相似文献
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An extension of two confirmatory factor models for multitrait-multimethod measurement designs with structurally different methods to the analysis of latent interaction effects is presented: the nonlinear latent difference (NL-LD) model and the nonlinear correlated trait–correlated method-minus-one (NL-CTC[M – 1]) model. Both models are compared with regard to (a) the psychometric definition of the latent variables, (b) the capabilities of explaining latent method effects, and (c) the analysis of latent interaction effects. Using the latent moderated structural equation approach, we show how moderated method effects can be examined in the NL-CTC(M – 1) model. This fine-grained analysis of method effects is not feasible using the classical NL-LD model. We propose an extended version of the NL-LD model, which recovers the results of the NL-CTC(M – 1) model. The different versions of the nonlinear multimethod models are illustrated using real data from a multirater study. Finally, the advantages and challenges of incorporating latent interaction effects in complex CFA–MTMM models are discussed. 相似文献
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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
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This conceptual paper reviews the extant literature on action research/teacher led inquiry and answers the question: How and in what circumstances can action research improve teachers’ classroom practice and therefore what might be the implications for school improvement? A critical analysis of the nature and purpose of action research as a mechanism for school improvement is explored via close examination of definitions, the characteristics of action research and models of action research. From the literature reviewed, it is noted that action research, whether conducted individually or collaboratively, has been found to contribute to teachers’ ability to investigate their practice with a view to improving students’ outcomes and for school improvement. Nevertheless, the success of action research is predicated on a number of conditions such as motivation, trust, mutual respect, and resources, particularly time spent within the situational context. Additionally, in educational contexts, action research is generally externally mandated, and tends to take place as a fulfillment for programs of higher education which are targeted at improving practice in settings such as schools and classrooms. Under these circumstances action research does lead to school and classroom improvement. Still, these circumstances can be called ideal and as such the question of institutionalizing action research as part of the routine of schools globally remains a challenge. Still, however, action research has the potential for improvement at both the individual and institutional level once the conditions are right. 相似文献
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Structural equation models with interaction and quadratic effects have become a standard tool for testing nonlinear hypotheses in the social sciences. Most of the current approaches assume normally distributed latent predictor variables. In this article, we describe a nonlinear structural equation mixture approach that integrates the strength of parametric approaches (specification of the nonlinear functional relationship) and the flexibility of semiparametric structural equation mixture approaches for approximating the nonnormality of latent predictor variables. In a comparative simulation study, the advantages of the proposed mixture procedure over contemporary approaches [Latent Moderated Structural Equations approach (LMS) and the extended unconstrained approach] are shown for varying degrees of skewness of the latent predictor variables. Whereas the conventional approaches show either biased parameter estimates or standard errors of the nonlinear effects, the proposed mixture approach provides unbiased estimates and standard errors. We present an empirical example from educational research. Guidelines for applications of the approaches and limitations are discussed. 相似文献
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