Measuring Search Engine Quality   总被引：12，自引：3，他引：9  

David Hawking  Nick Craswell  Peter Bailey  Kathleen Griffihs 《Information Retrieval》2001,4(1):33-59

The effectiveness of twenty public search engines is evaluated using TREC-inspired methods and a set of 54 queries taken from real Web search logs. The World Wide Web is taken as the test collection and a combination of crawler and text retrieval system is evaluated. The engines are compared on a range of measures derivable from binary relevance judgments of the first seven live results returned. Statistical testing reveals a significant difference between engines and high intercorrelations between measures. Surprisingly, given the dynamic nature of the Web and the time elapsed, there is also a high correlation between results of this study and a previous study by Gordon and Pathak. For nearly all engines, there is a gradual decline in precision at increasing cutoff after some initial fluctuation. Performance of the engines as a group is found to be inferior to the group of participants in the TREC-8 Large Web task, although the best engines approach the median of those systems. Shortcomings of current Web search evaluation methodology are identified and recommendations are made for future improvements. In particular, the present study and its predecessors deal with queries which are assumed to derive from a need to find a selection of documents relevant to a topic. By contrast, real Web search reflects a range of other information need types which require different judging and different measures.  相似文献   

The Provision for Personal, Social, Health Education (PSHE) and Citizenship in School-based Elements of Primary Initial Teacher Education     

Nick Mead 《Pastoral Care in Education》2004,22(2):19-26

This small-scale research study looks at the PSHE/Citizenship framework and the opportunities for student teachers to understand and experience within school the relationship between values, personal and social development and learning. A questionnaire was given to two sets of student teachers on their final school-based placements. The research suggests that there needs to be greater recognition of the centrality of multi-cultural awareness and understanding within the political literacy section of the PSHE/Citizenship framework. This is the counterpart to a previous study of the opportunities for values education within the university-based elements of Primary Initial Teacher Education ( Mead, 2003 ).  相似文献   

Planning for the future: learning from the past     

Nick Gibbs Director of Community Services 《Cultural Trends》2004,13(3):37-39

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Antecedent and consequent stimuli in teacher-child dyads     

M F Harrison  T L Layton  T D Taylor 《American annals of the deaf》1987,132(3):227-231

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Public library trends     

Nick Moore 《Cultural Trends》2004,13(1):27-57

Public libraries tend to be taken for granted. They can be found in nearly every community and are used by a substantial proportion of the population, particularly the young and the old. Yet the public library service, as it is today, is a relatively recent phenomenon. Despite their origins in the mid-19th century, the widespread network of public libraries is largely the product of the post-war welfare state. The demand for the service grew rapidly during the war and in the immediate post-war period. Provision to meet the demand was constrained initially by the competing demands for reconstruction, but by 1960 the service was ready to expand. The growth was consolidated by the 1964 Public Libraries and Museums Act and was given further emphasis by the 1962 Bourdillon standards (Ministry of Education, 1962). The Act and the standards provided the impetus for what might be described as the golden age of public libraries. This brief period was brought to an abrupt end by the economic crises of the mid-1970s and the subsequent downward pressure on public expenditure. The service managed to hold its own during the late 1970s and early 1980s but since then it has been in decline, with the rate of decline accelerating during the 1990s as new requirements and increasing costs stretched diminishing resources even further, to the point where the overall level of provision now falls well short of the basic standards that were considered to be essential in the early 1960s.  相似文献   

Academic achievement following childhood brain disease: implications for the concept of learning disabilities.     

H G Taylor  C Schatschneider 《Journal of learning disabilities》1992,25(10):630-638

The present study examined three hypotheses regarding the consequences of early brain damage for academic achievement: First, early brain insults will have a negative impact on achievement, even in children with normal intelligence. Second, underachievement in these children will be at least partially independent of IQ (i.e., not fully accounted for by a lowering of IQ within the average range). Third, normally intelligent children with histories of brain insult will also manifest selective cognitive dysfunctions. To test these hypotheses, we compared two groups of children who had recovered from Haemophilus influenzae type b meningitis. The "complicated" group consisted of children who, as a consequence of having sustained neurologic complications during their illness, were more likely to have had brain insults. Children in the "uncomplicated" group did not have complications with their illness and were regarded as having escaped significant central nervous system (CNS) pathology. Only children with normal hearing and a prorated Full Scale IQ of at least 80 (WISC-R) were considered. Group differences on the Wide Range Achievement Test-Revised were consistent with the first two hypotheses. Although the two groups had similar Verbal IQs, the complicated group also had a lower mean Performance IQ and performed less well on perceptually demanding neuropsychological tasks. Findings suggest that learning disabilities may have selective, brain-related cognitive antecedents; but they challenge the practice of using IQ criteria for clinical diagnosis.  相似文献   

Quality and relevance of domain-specific search: A case study in mental health     

Thanh Tin Tang  Nick Craswell  David Hawking  Kathy Griffiths  Helen Christensen 《Information Retrieval》2006,9(2):207-225

When searching for health information, results quality can be judged against available scientific evidence: Do search engines return advice consistent with evidence based medicine? We compared the performance of domain-specific health and depression search engines against a general-purpose engine (Google) on both relevance of results and quality of advice. Over 101 queries, to which the term ‘depression’ was added if not already present, Google returned more relevant results than those of the domain-specific engines. However, over the 50 treatment-related queries, Google returned 70 pages recommending for or against a well studied treatment, of which 19 strongly disagreed with the scientific evidence. A domain-specific index of 4 sites selected by domain experts was only wrong in 5 of 50 recommendations. Analysis suggests a tension between relevance and quality. Indexing more pages can give a greater number of relevant results, but selective inclusion can give better quality.  相似文献   

Reinventing the public value of libraries     

Nick Field 《Public Library Quarterly》2018,37(2):113-126

ABSTRACT

Libraries worldwide have had to re-think their purpose and adapt to changing community needs and expectations. They are no longer simply repositories for old books. Rather, they are vital components of a community’s social and economic infrastructure that connects communities and fosters creativity and innovation. This paper explores the changing role of libraries—and public value organizations more broadly—in creating positive social, economic, and environmental outcomes for individuals and communities.  相似文献   

‘Me Write Myself’: The Free Aboriginal Inhabitants of Van Diemen’s Land at Wybalenna, 1832–47     

Rebe Taylor 《档案与原稿》2019,47(1):172-174

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Science Instruction for Students with Learning Disabilities: A Meta‐Analysis     

William J. Therrien  Jonte C. Taylor  John L. Hosp  Erica R. Kaldenberg  Jay Gorsh 《Learning disabilities research & practice》2011,26(4):188-203

Although science has received much attention as a political and educational initiative, students with learning disabilities (LD) perform significantly lower than their nondisabled peers. This meta‐analysis evaluates the effectiveness of instructional strategies in science for students with LD. Twelve studies were examined, summarized, and grouped according to the type of strategy implemented. Effect sizes (ES) were calculated for each study. Across all studies, a mean ES of .78 was obtained, indicating a moderate positive effect on students with LD science achievement. Findings also align with past reviews of inquiry‐based instruction for students with special needs, indicating that students with LD need structure within an inquiry science approach in order to be successful. Additionally, results suggest that mnemonic instruction is highly effective at increasing learning disabled students' acquisition and retention of science facts.  相似文献