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991.
Student difficulties in science learning are frequently attributed to misconceptions about scientific concepts. We argue that domain‐general perceptual processes may also influence students' ability to learn and demonstrate mastery of difficult science concepts. Using the concept of center of gravity (CoG), we show how student difficulty in applying CoG to an object such as a baseball bat can be accounted for, at least in part, by general principles of perception (i.e., not exclusively physics‐based) that make perceiving the CoG of some objects more difficult than others. In particular, it is perceptually difficult to locate the CoG of objects with asymmetric‐extended properties. The basic perceptual features of objects must be taken into account when assessing students' classroom performance and developing effective science, technology, engineering, and mathematics (STEM) teaching methods.  相似文献   
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Recent theory and results from twin and adoption studies of children and adolescents suggest greater genetic influence on aggressive as compared to nonaggressive antisocial behavior. In addition, quantitative or qualitative differences in the etiology of these behaviors in males and females have been indicated in the literature. The Child Behavior Checklist was completed by the parents of 1022 Swedish twin pairs aged 7-9 years and of 501 British twin pairs aged 8-16 years. Genetic factors influenced aggressive antisocial behavior to a far greater extent than nonaggressive antisocial behavior, which was also significantly influenced by the shared environment. There was a significant sex difference in the etiology of nonaggressive antisocial behavior. Bivariate analyses supported the conclusion that the etiologies of aggressive and nonaggressive antisocial behavior differ for males and females.  相似文献   
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This study examines several key design elements of 37 academic library Web sites (members of the Association of Southeastern Research Libraries) and how they have changed between 2012 and 2015. While several studies have reviewed library Web sites looking for common design elements and content, the present work may be the first to look at the design elements of a large group of library Web sites over time. This study has two main goals: to present an objective analysis of the navigation and search interface designs at research university library Web sites, and to assess the usage of Web-scale discovery systems and content management systems in libraries. Other areas explored include when sites were most recently redesigned and whether sites have adopted a mobile-friendly, responsive design. Notable findings include a very high usage of Web-scale discovery systems, an increasing adoption of open source content management systems, and increasing implementation of responsive design. Also noted was a strong and growing standardization in navigation design. This study concludes with a review of the trends and discussion of current design patterns in academic library Web sites.  相似文献   
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