共查询到20条相似文献，搜索用时 62 毫秒
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如何查找隐形网页资源 总被引：2，自引：0，他引：2
王丹 《中国科技资源导刊 (中国信息导报)》2005,(4):55-57
众所周知,互联网是各类信息的存储器,是一本包罗万象的百科全书。为了使每一个用户都能更有效地获取其所需要的信息,大量的搜索引擎在网上涌现,其中包括Google、Yahoo、Infoseek等。一般来说,这些搜索引擎用URL和关键词来标引和存储其数据库中的网页,当用户提出查询请求时,搜索引擎首先根据数据库中所存储的网页的URL来搜索网页,并返回相关的结果。然而,这些搜索引擎并不能搜索互联网上的所有信息。最近人们注意到一种叫"invisibleweb"的网页,这种网页又被称为"deep"或隐形网页。简单地说,就是那些因为各种原因不能被普通搜索引擎如Google、Yahoo等搜索到的网页。据 相似文献
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搜索引擎中Robot搜索算法的优化 总被引：15，自引：0，他引：15
目前的搜索引擎越来越暴露出不足之处 ,当用户使用搜索引擎时输入特定关键词之后 ,返回的查询结果往往有数千甚至几百万之多 ,而且其中包含大量的重复信息与垃圾信息 ,用户从中筛选出自己感兴趣的网页仍然需要耗费很长的时间。另外一种情况就是 ,Web上明明存在某些重要网页 ,却没有被搜索引擎的robot发现。本文针对这种现象 ,重点讨论搜索引擎中的搜索策略 ,改善搜索算法 ,使Robot在搜索阶段就能够充分处理与Robot频繁交互的URL列表。根据网页的内容、HTML结构以及其中包含的超链信息计算网页的PageRank ,使URL列表能够根据重要性调整排列顺序。初步的试验结果表明 ,本文的优化算法可以较大程度地改进搜索引擎的整体性能 相似文献
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元搜索引擎的发展悖论及建议 总被引：1，自引：0，他引：1
王雁杰 《科技文献信息管理》2004,18(2):4-6,14
文章通过对部分有代表性的元搜索引擎和独立搜索引擎的对比研究发现元搜索引擎的返回结果在数量和覆盖范围上远比独立搜索引擎小，进而提出元搜索引擎面临着一个“发展悖论”，最后给出元搜索引擎走出困境的方法建议。 相似文献
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中文元搜索引擎成员搜索引擎的选择策略研究 总被引：2，自引：0，他引：2
针对目前中文元搜索引擎在成员搜索引擎选择方面的不足,作者详细讨论了一种分类分组的选择策略.即在元搜索引擎上增加信息类别选项.系统预先设置合理的信息类别,再在各类别下分别列出适合该类别的搜索引擎组合供用户选择.这些组合剔除了那些没有提供该信息类型搜索的普通搜索引擎,同时向用户推荐几个适合其搜索请求的成员搜索引擎组供其选择,通过这一设置,元搜索引擎既可以满足用户使用偏好又可以避免一些不必要的搜索,从而提高搜索的效率和准确度. 相似文献
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中文元搜索引擎万纬搜索研究 总被引：11，自引：0，他引：11
李明 《现代图书情报技术》2003,(5):48-50,54
分析了中文元搜索引擎万纬搜索的使用特色，研究了万纬搜索与国外优秀元搜索引擎的差距，探讨了中文元搜索引擎的发展方向。 相似文献
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基于本体进行自动分类的元搜索引擎的设计与实现 总被引：1，自引：0，他引：1
王梅文 《现代图书情报技术》2008,24(9):58-63
研究基于本体对元搜索引擎查询结果进行自动分类的方法,依据事先构建的药学本体,实现基于本体对元搜索引擎的网页结果进行自动分类的实验系统,形成层次清晰、逻辑合理的分类显示结果界面。最后对实验系统的准确度进行评价,网页分类基本取得预期的效果。 相似文献
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基于XML的智能元搜索引擎研究 总被引：1，自引：0，他引：1
介绍一种基于XML和Agent技术的智能元搜索引擎系统。该系统采用元搜索引擎的结构，以Agent作为架构系统的基本组件，利用Agent的自治性和协作性来完成用户个性化信息的搜索；利用XML和XSL分别在结构化信息表达方面，在信息显示、转换方面的优点，来实现元搜索引擎的扩展性以及搜索结果的个性化输出。最后探讨XML和XSL在查询请求和搜索结果转换上的应用以及基于XML的Agent通信。 相似文献
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The authors of this paper investigated the impact of the advanced search features of three common search engines on retrieval result performance: Yahoo, Google, and Live Search. The authors analyzed 240 search queries with different information need emphases to determine retrieval effectiveness differences among regular search, title search, exact phrase search, and PDF file format restriction search. A one-way ANOVA method and regression analysis method were used for the study. It was found that the PDF file format restriction search achieved the best retrieval performance among Yahoo, Google and Live Search. The regular search achieved the best web page ranking performance among Yahoo, Google, and Live Search. The findings of this study can be used to assist users in formulating an appropriate search strategy to improve search effectiveness, and to shed light on how search engines react to different types of search features in terms of retrieval effectiveness. 相似文献
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中文搜索引擎的搜索结果重合率研究 总被引：1，自引：0，他引：1
本文的研究目的是测试主流中文搜索引擎搜索结果之间的重合程度和差异程度.利用一个具有11 171条来自真实用户的提问样本集对百度、谷歌和中国雅虎进行实际测试,发现中文搜索引擎搜索结果之间的差异很大,重合率很低.在全部的第一页搜索结果中,三个引擎中任何一个引擎独有的搜索结果总数占89.34%,任何两个引擎之间重合的搜索结果总数占8.11%,三个引擎重合的搜索结果数量占2.54%.三个引擎前两页搜索结果的重合比例更低.通过和已有的英文搜索引擎重合率测试数据相比较,发现中英文搜索引擎的搜索结果重合率都很低,且很相近. 相似文献
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The authors of this paper investigated the impact of the advanced search features of three common search engines on retrieval result performance: Yahoo, Google, and Live Search. The authors analyzed 240 search queries with different information need emphases to determine retrieval effectiveness differences among regular search, title search, exact phrase search, and PDF file format restriction search. A one-way ANOVA method and regression analysis method were used for the study. It was found that the PDF file format restriction search achieved the best retrieval performance among Yahoo, Google and Live Search. The regular search achieved the best web page ranking performance among Yahoo, Google, and Live Search. The findings of this study can be used to assist users in formulating an appropriate search strategy to improve search effectiveness, and to shed light on how search engines react to different types of search features in terms of retrieval effectiveness. 相似文献
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徐芳 《现代图书情报技术》2009,25(5):81-85
介绍一种新的站内搜索引擎实现,它是基于Google、Baidu等大型通用搜索引擎实现站内搜索的二次开发。与其他类似应用相比其优点是：搜索结果页面干净、无其他广告、推广信息等附加内容;能同时指定多个域名,达到在主网站、子网站及类网站间同时搜索的目的。 相似文献
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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
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Objective
The purpose of this study was to investigate the relative effectiveness of three web-scale discovery (WSD) tools in answering health sciences search queries.Methods
Simple keyword searches, based on topics from six health sciences disciplines, were run at multiple real-world implementations of EBSCO Discovery Service (EDS), Ex Libris''s Primo, and ProQuest''s Summon. Each WSD tool was evaluated in its ability to retrieve relevant results and in its coverage of MEDLINE content.Results
All WSD tools returned between 50%–60% relevant results. Primo returned a higher number of duplicate results than the other 2 WSD products. Summon results were more relevant when search terms were automatically mapped to controlled vocabulary. EDS indexed the largest number of MEDLINE citations, followed closely by Summon. Additionally, keyword searches in all 3 WSD tools retrieved relevant material that was not found with precision (Medical Subject Headings) searches in MEDLINE.Conclusions
None of the 3 WSD products studied was overwhelmingly more effective in returning relevant results. While difficult to place the figure of 50%–60% relevance in context, it implies a strong likelihood that the average user would be able to find satisfactory sources on the first page of search results using a rudimentary keyword search. The discovery of additional relevant material beyond that retrieved from MEDLINE indicates WSD tools'' value as a supplement to traditional resources for health sciences researchers. 相似文献18.
传统搜索引擎通常靠抓取全文关键词进行分析,由此带来三大缺陷:缺乏语义描述导致查准率低;检索结果冗余模糊导致检索效率低;检索途径不足。基于DC元数据描述网络资源的优越性,课题组设计了一个基于DC元数据的网络搜索引擎系统DCSE,力图克服传统搜索引擎的上述缺陷。DCSE系统自动抓取含DC描述的Web网页,把DC描述信息存入到数据库,排序索引后提供用户检索。检索界面设计成以15个DC元素为检索项的多项逻辑组合检索,检索结果以各DC元素的描述内容来显示,如标题、创建者、描述、日期等。用户通过多项组合检索提高查准率,并通过清晰的结果显示对所需信息做出快速判断、选择,从而达到提高检索效率的目的。 相似文献
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Measuring Search Engine Quality 总被引：12，自引：3，他引：9
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
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Anchor texts complement Web page content and have been used extensively in commercial Web search engines. Existing methods
for anchor text weighting rely on the hyperlink information which is created by page content editors. Since anchor texts are
created to help user browse the Web, browsing behavior of Web users may also provide useful or complementary information for
anchor text weighting. In this paper, we discuss the possibility and effectiveness of incorporating browsing activities of
Web users into anchor texts for Web search. We first make an analysis on the effectiveness of anchor texts with browsing activities.
And then we propose two new anchor models which incorporate browsing activities. To deal with the data sparseness problem
of user-clicked anchor texts, two features of user’s browsing behavior are explored and analyzed. Based on these features,
a smoothing method for the new anchor models is proposed. Experimental results show that by incorporating browsing activities
the new anchor models outperform the state-of-art anchor models which use only the hyperlink information. This study demonstrates
the benefits of Web browsing activities to affect anchor text weighting. 相似文献