The impact of environmental factors on components of reading and dyslexia     

Stefan?SamuelssonEmail author  Ingvar?Lundberg 《Annals of dyslexia》2003,53(1):201-217

Data from 123 male adults were analyzed to estimate environmental influences on components of literacy skills and to explore the impact of environmental factors in different approaches to define reading difficulty. Literacy skills were decomposed into general cognitive function, reading comprehension, spelling, word reading, and phonological ability. Environmental factors examined were related to home conditions, school conditions, and literacy environment. Results suggest that there is a substantial social-cultural bias in the delineation of literacy skills and in the definitions of reading disabilities. Results also suggest that phonological ability constitutes the only measure relatively unaffected by environmental influences. This study has brought forward a new argument for emphasizing phonological deficits as the core component in defining dyslexia.  相似文献   

Parametrization of the solvent action on modern artists' paint systems     

Stefan Zumbühl 《文物保护研究》2014,59(1):24-37

A solvent action parametrization scheme has been developed combining relevant parameters of the solvent action on modern artists' paints to characterize the solvation and dissolving properties of different binding media. The new system combines different concepts used in solvent chemistry. It is based on the normalized and solute-dependent dimension [hδ_H + eE_T(30)cv]^N. It comprises a polarity value E_T(30)cv as the magnitude of the enthalpy, and a combined value representing the cavitation energy δ_H as an entropy-influencing factor. Forty-eight solvents were divided into five subgroups based on their interaction and structural properties. This binary scheme permits to reliably quantify spaces of efficiency. The graphical selectivity of the scheme was applied to four binding media systems (oil, alkyd, acrylic-, and acrylic-polystyrene) by determination of the swelling capacity of 48 solvents. The graphical visualization of the systematic parametrization of solvents permits one to judge the intermolecular interaction and other effects of solvation relevant to the restoration of painted artwork.  相似文献   

Relational integration as a predictor of academic achievement     

Stefan Krumm  Anastasiya A. Lipnevich  Lothar Schmidt-Atzert  Markus Bühner 《Learning and individual differences》2012,22(6):759-769

The current study aimed at applying a broad model of cognitive functions to predict performance in science and language courses at school as well as performance in a science course at university. We hypothesized that performance in science courses was predominantly related to the cognitive function known as relational integration, whereas performance in language courses should be best explained by individuals' short-term memory capacity. The sample consisted of 161 German undergraduate students who were asked to complete 33 cognitive tasks. School grades were also obtained. The analyses revealed that relational integration incrementally explained variance in science grades. Short-term memory acted as a predictor of language grades. However, mental speed was also substantially related to language grades. Predicting university exam scores revealed that short-term memory yielded an incremental predictive power. We conclude that academic performance requires different cognitive functions depending on a domain of study.  相似文献   

How and why do students of higher education participate in online seminars?     

Stefan Hrastinski  Jimmy Jaldemark 《Education and Information Technologies》2012,17(3):253-271

Online education is continuing to gain popularity in educational institutions and organizations. Hitherto, most research has occurred at aggregated levels, while few researchers have studied how and why individuals participate in online education. It is essential to examine individual perceptions and relationships in order to understand how students behave in relation to others. This paper investigates how students of higher education participate in online seminars and why they participate in certain ways. An online class that attended asynchronous and synchronous online seminars was studied. Electronic logs were used to examine how students participated and interviews were used to illustrate why they participated. It was revealed that the participation of students varied between aspects such as exchanging information, managing tasks and providing social support and the emphasis of these aspects were related to the tool they communicated through. A number of participation inhibitors were identified and it was also suggested how these inhibitors can be addressed.  相似文献   

Beyond linearity: Using IRT-scaled level models to describe the relation between prior proportional reasoning skills and fraction learning outcomes     

Constanze Schadl  Stefan Ufer 《Child development》2023,94(6):1642-1658

Previous research on the role of prior skills like proportional reasoning skills for the development of mathematical concepts offers conclusions such as “more (prior skills) is better (for later learning).” Insights, which prior skill level goes along with which level of learning outcomes, may advance the understanding of the development of mathematical concepts. An exploratory approach is presented based on level models to describe the relation between symbolic proportional reasoning skills and fraction outcomes beyond linearity. Analyses draw on samples of German fourth to sixth graders from a scaling (2017, N = 325, 54.8% female) and longitudinal study (2018/2019, N = 436, 42.7% female). Particularly mastering natural and internal rational ratios in proportional reasoning seems relevant for successful fraction learning.  相似文献