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11.
In the IR field it is clear that the value of a system depends on the cost and benefit profiles of its users. It would seem obvious that different users would prefer different systems. In the TREC-9 filtering track, systems are evaluated by a utility measure specifying a given cost and benefit. However, in the study of decision systems it is known that, in some cases, one system may be unconditionally better than another. In this paper we employ a decision theoretic approach to find conditions under which an Information Filtering (IF) system is unconditionally superior to another for all users regardless of their cost and benefit profiles.It is well known that if two IF systems have equal precision the system with better recall will be preferred by all users. Similarly, with equal recall, better precision is universally preferred. We confirm these known results and discover an unexpected dominance relation in which a system with lower recall will be universally preferred provided its precision is sufficiently higher. 相似文献
12.
Edward A. Holdaway 《Higher Education Quarterly》1993,47(3):237-258
Many western countries are paying increasing attention to the organization and administration of graduate studies. Such attention has developed from primary concerns about completion times, completion percentages, programme quality, and student quality, as well as secondary concerns about supervisors, funding, coursework, inter-organizational co-operation, and policies and practices of both universities and research councils. Using information about British graduate programmes as a basis, the article presents policy issues related to research councils, funding councils, and control, followed by discussion of the themes of the nature of programmes, supervision and evaluation, completion time, quality, and innovation. The final sections address several concerns and offer some suggestions. 相似文献
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