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Jovan?PehcevskiEmail author James?A.?Thom Anne-Marie?Vercoustre 《Information Retrieval》2005,8(4):571-600
This paper investigates the impact of three approaches to XML retrieval: using Zettair, a full-text information retrieval system; using eXist, a native XML database; and using a hybrid system that takes full article answers from Zettair and uses eXist to extract elements from those articles. For the content-only topics, we undertake a preliminary analysis of the INEX 2003 relevance assessments in order to identify the types of highly relevant document components. Further analysis identifies two complementary sub-cases of relevance assessments (General and Specific) and two categories of topics (Broad and Narrow). We develop a novel retrieval module that for a content-only topic utilises the information from the resulting answer list of a native XML database and dynamically determines the preferable units of retrieval, which we call Coherent Retrieval Elements. The results of our experiments show that—when each of the three systems is evaluated against different retrieval scenarios (such as different cases of relevance assessments, different topic categories and different choices of evaluation metrics)—the XML retrieval systems exhibit varying behaviour and the best performance can be reached for different values of the retrieval parameters. In the case of INEX 2003 relevance assessments for the content-only topics, our newly developed hybrid XML retrieval system is substantially more effective than either Zettair or eXist, and yields a robust and a very effective XML retrieval. 相似文献
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Research shows that formative assessment can exert a powerful effect on student learning, yet the complexity of formative assessment is not well understood and some curricular structures and practices do not fully exploit its potential. This article outlines the background to the political promotion of employability and shows that institutional responses are influenced by multiple considerations. It discusses formative assessment and models it as a complex signalling system before considering the implications, for students’ employability, of accentuating the attention given to formative assessment. The potential for action is discussed with reference to three levels: those of the institution, the department, and the individual academic. 相似文献
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The European higher education landscape is inhabited by three clans: the Euro-philiac, his wicked twin, the Euro-phobic and most interesting of all, the Euro-sceptic. This unholy trinity has long been with us. Though the recent Euro electoral fiasco has in all probability served to bolster the ranks of the second and third tribes1 相似文献
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This paper identifies two conceptions of security in contemporary concerns over the vulnerability of computers and networks
to hostile attack. One is derived from individual-focused conceptions of computer security developed in computer science and
engineering. The other is informed by the concerns of national security agencies of government as well as those of corporate
intellectual property owners. A comparative evaluation of these two conceptions utilizes the theoretical construct of “securitization,”developed
by the Copenhagen School of International Relations.
This article has been on the drawing boards for longer than I dare to admit. Along the way, many have helped its development
by generously sharing their wisdom: James Der Derian, Niva Elkin-Koren, Ed Felten, Batya Friedman, Lene Hansen, audiences
at CEPE, TPRC, the Yale Cybercrime and Digital Law Enforcement Conference, and Watson Institute’s Symposium in Dis/Simulations
of War and Peace,” and University of Newcastle, Computer Science Department. Thanks, also, to Sam Howard-Spink for excellent
editorial assistance. 相似文献