System Performance and Natural Language Expression of Information Needs   总被引：1，自引：0，他引：1  

Walter Liggett  Chris Buckley 《Information Retrieval》2005,8(1):101-128

Consider information retrieval systems that respond to a query (a natural language statement of a topic, an information need) with an ordered list of 1000 documents from the document collection. From the responses to queries that all express the same topic, one can discern how the words associated with a topic result in particular system behavior. From what is discerned from different topics, one can hypothesize abstract topic factors that influence system performance. An example of such a factor is the specificity of the topic's primary key word. This paper shows that statements about the effect of abstract topic factors on system performance can be supported empirically. A combination of statistical methods is applied to system responses from NIST's Text REtrieval Conference. We analyze each topic using a measure of irrelevant-document exclusion computed for each response and a measure of dissimilarity between relevant-document return orders computed for each pair of responses. We formulate topic factors through graphical comparison of measurements for different topics. Finally, we propose for each topic a four-dimensional summarization that we use to select topic comparisons likely to depict topic factors clearly.  相似文献   

Book reviews     

Chris Nash  Edward Hagerman  Richard Hoggart 《Interchange》1986,17(1):88-95

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The impact of national curriculum assessment arrangements on english teachers' thinking and classroom practice in english secondary schools     

Paul Cooper  Chris Davies 《Teaching and Teacher Education》1993,9(5-6)

This paper reports a study of the ways in which teachers' thinking and classroom practice are influenced by innovations that are imposed by government. The particular focus of this paper is English teachers' responses to the Standard Assessment Tasks (SATs) for 14-year-olds in England and Wales, which were set for the first time in June 1993.  相似文献   

Place conditioning with d-amphetamine: The effect of the CS-UCS interval and evidence of a place avoidance     

Anne -Marie Wall  Riley E. Hinson  Eileen Schmidt  Chris Johnston  Angela Streather 《Learning & behavior》1990,18(4):393-400

In Experiment 1, a dose-response study of place conditioning with amphetamine was conducted. Male Sprague-Dawley rats receiving 0.0, 0.05, 0.1, 0.5, 2.0, 5.0, 7.5, or 10.0 mg/kg of d-amphetamine underwent 104-day cycles of place conditioning. On alternate days, each rat was injected with its designated dose of amphetamine while confined to its originally nonpreferred end of a three-compartment, straight alley box. On intervening days, each rat was injected with saline while confined to its originally preferred compartment. Following each 4-day cycle, a choice test was administered in which each rat was allowed 20 min of access to the entire alley box. Doses of amphetamine (≥0.5 mg/kg) induced a significant avoidance of the compartment in which amphetamine had been administered. In Experiment 2, animals received 0.0, 0.5, 2.0, or 5.0 mg/kg of amphetamine and underwent place conditioning procedures identical to those for the animals in Experiment 1. Unlike in Experiment 1, the animals were given a single choice test following 104-day place conditioning cycles. All groups that received amphetamine exbibited-a-eonditioned place avoidance. In Experiment 3, the effect of various CS-UCS intervals on place conditioning with 2.0 mg/kg of amphetamine was examined. Animals that received amphetamine immediately following their removal from the chamber exhibited a conditioned place avoidance.  相似文献   

Popular Music Media Education     

Chris Richards 《Discourse: Studies in the Cultural Politics of Education》1995,16(3):317-330

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The Paget-Gorman System     

Michael Megee  Jacqueline A. Rowe  Chris Kiernan  Barbara Reid  Linda Jones 《British Journal of Special Education》1983,10(2):32-32

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Mindweave: communication,computers and distance education     

Chris Colbourn 《Instructional Science》1990,19(1):85-87

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Stress,health and schoolteachers: a comparison with other professions     

Chris Kyriacou 《Cambridge Journal of Education》1980,10(3):154-159

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Integrating schematic representations of knowledge: A theoretical stimulus to science educators?     

Jack Rowell  Chris Dawson 《Research in Science Education》1986,16(1):226-232

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Building preservation functionality in a digital archive: the National Library of The Netherlands     

Chris Bellekom 《Learned Publishing》2004,17(4):275-280

An increasing volume of information exists only in digital form. It can be scanned material; material actually created as digital publications; or material created as part of the day‐to‐day business of an organization. In The Netherlands, initiatives such as the ‘Memory of The Netherlands’ have emerged, creating a demand for good‐quality digital materials to support them. Many other digitization initiatives are constantly being announced. The digital form offers many advantages but presents challenges in respect of preservation and of changes in platforms and software.  相似文献