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991.
Open access (OA) literature is digital, online, free of charge, and free of most copyright and licensing restrictions. The lack of clarity of publisher permissions for archiving in OA repositories affects the adoption of the green OA route. This paper explores editorial policies and self‐archiving conditions in 1,615 Spanish scholarly journals. 48% are published by university and research institutions, 25% by associations/societies, and 17% by commercial publishers; social sciences and humanities (SSH) accounted for 67% of the journals (44.5% and 22.5%, respectively) followed by health sciences (20%); 71% offered gratis access immediately after publication, and 11% after an embargo; 31% provided some mention of author rights. Self‐archiving was specifically allowed by 65% of the journals; 52% were classified as ROMEO‐blue, 12% as green and 15% as white, and 21% could not be classified; 21%, mostly in SSH, used some type of Creative Commons license. 相似文献
992.
Helen S. Du Samuel K.W. Chu Gary E. Gorman Felix L.C. Siu 《Library & information science research》2014
Three groups of social bookmarking users, namely experienced users, users with moderate level of experience, and novice users, were investigated, in terms of their reported tagging behaviors, perceived usefulness of social bookmarking in information discovery and management, and perceived usefulness of the bookmarking features provided. Based on the empirical analysis of the Connotea users, who are primarily in academia, the study shows that experienced academic users generally prefer to use social bookmarking while moderately experienced and novice users still prefer to use the traditional bookmarking methods, such as creating and using bookmarks on a dedicated computer. Experienced academic users were also found to create more tags per bookmark comparing to the other two groups. Most novice academic users, however, only created one tag per bookmark, which just met Connotea's minimum requirement. Surprisingly different from the collaborative design nature of the social bookmarking systems, the study finds that our participants, particularly experienced academic users, prefer to create and use their own bookmarks rather than sharing bookmarks created by others. In fact, experienced users have significantly higher frequency (once every two weeks) of creating bookmarks than the other two groups (once a month or less). In addition, website design features and functions, such as automatic collection of bibliographic information, are regarded by all participants as helpful for information discovery. The in-depth examination and discussion of the opinions of Connotea users may be useful for further improvement of the design features and usage applications, particularly for academic social bookmarking websites. The results may also have potential implications to the future development of social bookmarking services in general. 相似文献
993.
The amount that students read for enjoyment and for school is a major contributor to students' reading achievement and knowledge of the world. Consequently, it is important to identify the factors that predict amount of reading. A literature review revealed that motivation, strategy-use, and past reading achievement all may be expected to predict reading amount. To examine these variables, a total of 251 students in Grades 3 and 5 was administered questionnaires of these constructs and a reading test. Results showed that amount of reading for enjoyment was predicted most highly by motivation, when all other variables were controlled statistically in multiple-regression analyses. In contrast, amount of reading for school was predicted most highly by strategy use, when all other variables were controlled. However, these predictions were different for students in Grades 3 and 5. Findings of the study indicate that amount of reading is multiply determined by cognitive and motivational constructs, which is consistent with an engagement perspective on reading development. Copyright 2001 Academic Press. 相似文献
994.
H.E. Suess 《Endeavour》1980,4(3):113-117
Radiocarbon dating is, and remains, one of the most powerful methods of dating archaeological artefacts. Initially, it was assumed that the carbon-14 content of atmospheric carbon dioxide had remained constant, but latterly it has been shown that this assumption is not valid. It has now proved possible, mainly by correlation with tree-growth rings, to measure historic fluctuations in carbon-14 content and to make the necessary corrections—of up to one thousand years—to the conventionally calculated dates. 相似文献
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Leslie E. Simon 《Journal of The Franklin Institute》1944,237(5):359-370
It is shown that wrong inferences are drawn from samples because of failure to understand what constitutes a lot and because of failure to verify the existence of a lot in the practically useful sense. Time-tried methods of making valid inferences from samples without increased cost are pointed out. 相似文献