首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
This papers studies a special “small” information retrieval problem where user satisfaction only depends on the ordering of documents. We look for a retrieval performance measure applicable for this setting. We define some requirements for such a measure. We develop a theoretical ordering of all outcomes. We look at some standard and purpose-build measures and assess them against the requirements. We conclude that a linear combination of two such measures is adequate.  相似文献   

2.
韩永青 《情报科学》2006,24(7):1078-1081
本文从用户问题索解机制入手,介绍问题索解的基本原理,分析用户在信息检索过程中的问题索解机制,认为用户信息检索的问题索解过程可以分为五个阶段,即信息识别阶段、信息表征阶段、信息检索策略调整阶段、信息反馈阶段和检索结果评价阶段。在分析用户信息检索机制的基础上,从用户的角度,为提高信息检索效率提出一些建议。  相似文献   

3.
吴丹  齐和庆 《现代情报》2009,29(7):215-221
信息检索发展中的一个重要理论问题是如何对查询与文档进行匹配,由此形成了不同的信息检索模型。跨语言信息检索是信息检索研究的一个分支,也是近年来的热点问题。本文主要对信息检索模型的研究进展,及其在跨语言信息检索中的应用进展进行分析与综述。  相似文献   

4.
信息检索结果如何更好地满足用户的信息需求是信息检索系统设计必须考虑的首要问题。本文从信息需求的层次理论出发,分析了用户信息需求的特点及信息需求与信息检索结果组织间的关系。在分析信息潜在需求构成的基础上,重点讨论了基于用户潜在信息需求满足的信息检索结果排序及聚类方式,对如何提高信息检索的效果给出了建议。  相似文献   

5.
Forty-eight years ago Maron and Kuhns published their paper, “On Relevance, Probabilistic Indexing and Information Retrieval” (1960). This was the first paper to present a probabilistic approach to information retrieval, and perhaps the first paper on ranked retrieval. Although it is one of the most widely cited papers in the field of information retrieval, many researchers today may not be familiar with its influence. This paper describes the Maron and Kuhns article and the influence that it has had on the field of information retrieval.  相似文献   

6.
This paper presents a probabilistic information retrieval framework in which the retrieval problem is formally treated as a statistical decision problem. In this framework, queries and documents are modeled using statistical language models, user preferences are modeled through loss functions, and retrieval is cast as a risk minimization problem. We discuss how this framework can unify existing retrieval models and accommodate systematic development of new retrieval models. As an example of using the framework to model non-traditional retrieval problems, we derive retrieval models for subtopic retrieval, which is concerned with retrieving documents to cover many different subtopics of a general query topic. These new models differ from traditional retrieval models in that they relax the traditional assumption of independent relevance of documents.  相似文献   

7.
A survey is given of the potential role of artificial intelligence in retrieval systems. Papers by Bush and Turing are used to introduce early ideas in the two fields and definitions for artificial intelligence and information retrieval for the purposes of this paper are given. A simple model of an information retrieval system provides a framework for subsequent discussion of artificial intelligence concepts and their applicability in information retrieval. Concepts surveyed include pattern recognition, representation, problem solving and planning, heuristics, and learning. The paper concludes with an outline of areas for further research on artificial intelligence in information retrieval systems.  相似文献   

8.
The term mismatch problem in information retrieval is a critical problem, and several techniques have been developed, such as query expansion, cluster-based retrieval and dimensionality reduction to resolve this issue. Of these techniques, this paper performs an empirical study on query expansion and cluster-based retrieval. We examine the effect of using parsimony in query expansion and the effect of clustering algorithms in cluster-based retrieval. In addition, query expansion and cluster-based retrieval are compared, and their combinations are evaluated in terms of retrieval performance by performing experimentations on seven test collections of NTCIR and TREC.  相似文献   

9.
基于Internet的高校图书馆集成化信息检索系统   总被引:1,自引:1,他引:1  
梁震戈  王文君  杨国福 《现代情报》2005,25(9):36-37,39
本文介绍了基于Internet的高校图书馆集成化信息检索系统所采用的各种技术、检索工具及其检索结果的显示功能。最后指出了在研究过程中遇到的一些问题。  相似文献   

10.
11.
[研究目的]反恐情报信息决策性证据的获取工作对反恐斗争的成败有着决定性的作用,故在此针对反恐情报信息决策性证据的智能检索机制展开研究。[研究方法]分析反恐情报信息的特征及反恐情报信息决策性证据在反恐决策中的作用,研究当前常用的反恐情报信息决策性证据检索方式与不足,针对已有检索方式的缺陷,为满足智能检索机制所需,提出并构建基于本体的反恐情报信息决策性证据智能检索机制,构建包含本体管理模块、用户问题处理模块、资源管理模块及智能检索主体模块等智能检索机制,并通过构建该智能检索机制实证模型,对该智能检索机制展开实证分析。[研究结论]结果表明,该智能检索机制的可靠性、安全性、可存取性、交互性及隐私性每提高1%,将会对反恐情报信息决策性证据获取成功率提高0.7701%~2.7990%,可为反恐情报信息分析与处理部门获取实时决策性证据奠定基础。  相似文献   

12.
网络环境下文献检索教学改革研究   总被引:12,自引:0,他引:12  
针对网络环境对文献检索教学的挑战,我们广泛开展了网络信息评价标准与方法、网络信息资源比较、检索策略构建方面的研究与教学实践,并加强教材建设,及时注意最新信息,建立了“以问题为中心”的教学模式,以求达到全面培养学生的信息素养与创新能力的目的。同时对计算机辅助教学设施在教学中的应用提出了自己的看法与思考。  相似文献   

13.
曲琳琳 《情报科学》2021,39(8):132-138
【目的/意义】跨语言信息检索研究的目的即在消除因语言的差异而导致信息查询的困难,提高从大量纷繁 复杂的查找特定信息的效率。同时提供一种更加方便的途径使得用户能够使用自己熟悉的语言检索另外一种语 言文档。【方法/过程】本文通过对国内外跨语言信息检索的研究现状分析,介绍了目前几种查询翻译的方法,包括: 直接查询翻译、文献翻译、中间语言翻译以及查询—文献翻译方法,对其效果进行比较,然后阐述了跨语言检索关 键技术,对使用基于双语词典、语料库、机器翻译技术等产生的歧义性提出了解决方法及评价。【结果/结论】使用自 然语言处理技术、共现技术、相关反馈技术、扩展技术、双向翻译技术以及基于本体信息检索技术确保知识词典的 覆盖度和歧义性处理,通过对跨语言检索实验分析证明采用知识词典、语料库和搜索引擎组合能够提高查询效 率。【创新/局限】本文为了解决跨语言信息检索使用词典、语料库中词语缺乏的现象,提出通过搜索引擎从网页获 取信息资源来充实语料库中语句对不足的问题。文章主要针对中英文信息检索问题进行了探讨,解决方法还需要 进一步研究,如中文切词困难以及字典覆盖率低等严重影响检索的效率。  相似文献   

14.
Conventional information retrieval technology (i.e. VSM) faces many difficulties when being implemented in complex P2P systems for the lack of global statistic information (e.g. IDF) and central services. In this paper, we suggest a novel query optimization scheme (Semantic Dual Query Expansion, SDQE) that makes full use of the context information supplied by the local document collection. Latent Semantic Indexing (LSI) is used to explore the local context information. By comparing the different local context information hidden in different document collections, it is possible to solve the synonymy–polysemy problem in VSM. The experiments prove that our scheme is effective to improve the retrieval performance in P2P systems without knowing the global statistic information.  相似文献   

15.
In information retrieval, cluster-based retrieval is a well-known attempt in resolving the problem of term mismatch. Clustering requires similarity information between the documents, which is difficult to calculate at a feasible time. The adaptive document clustering scheme has been investigated by researchers to resolve this problem. However, its theoretical viewpoint has not been fully discovered. In this regard, we provide a conceptual viewpoint of the adaptive document clustering based on query-based similarities, by regarding the user’s query as a concept. As a result, adaptive document clustering scheme can be viewed as an approximation of this similarity. Based on this idea, we derive three new query-based similarity measures in language modeling framework, and evaluate them in the context of cluster-based retrieval, comparing with K-means clustering and full document expansion. Evaluation result shows that retrievals based on query-based similarities significantly improve the baseline, while being comparable to other methods. This implies that the newly developed query-based similarities become feasible criterions for adaptive document clustering.  相似文献   

16.
To obtain high performances, previous works on FAQ retrieval used high-level knowledge bases or handcrafted rules. However, it is a time and effort consuming job to construct these knowledge bases and rules whenever application domains are changed. To overcome this problem, we propose a high-performance FAQ retrieval system only using users’ query logs as knowledge sources. During indexing time, the proposed system efficiently clusters users’ query logs using classification techniques based on latent semantic analysis. During retrieval time, the proposed system smoothes FAQs using the query log clusters. In the experiment, the proposed system outperformed the conventional information retrieval systems in FAQ retrieval. Based on various experiments, we found that the proposed system could alleviate critical lexical disagreement problems in short document retrieval. In addition, we believe that the proposed system is more practical and reliable than the previous FAQ retrieval systems because it uses only data-driven methods without high-level knowledge sources.  相似文献   

17.
FACTS is an APL-based interactive on-line system used for retrieval of budget and accounting data. The system provides selective retrieval and manipulation of financial data for management in a development laboratory. The terms “teilnehmer” and “teilhaber” are defined and it is argued that use of a teilnehmer system, such as APL, can considerably reduce the programming and monitary investment for information science systems applications. A brief discussion of APL's text editing facilities is also included to introduce this relatively unknown language to information scientists.  相似文献   

18.
Analyzing actions to be supported by information and information retrieval (IR) systems is vital for understanding the needs of different types of information, search strategies and relevance assessments, in short, understanding IR. A necessary condition for this understanding is to link results from information seeking studies to the body of knowledge by IR studies. The actions to be focused on in this paper are tasks from the angle of problem solving. I will analyze certain features of work tasks and relate these features to types of information people are looking for and using in their tasks, patterning of search strategies for obtaining information and relevance assessments in choosing retrieved documents. The major claim is that these information activities are systematically connected to task complexity and structure of the problem at hand. The argumentation is based on both theoretical and empirical results from studies on information retrieval and seeking.  相似文献   

19.
梁少星 《现代情报》2015,35(8):151-156
相似度计算方法的优劣直接影响到信息检索与推荐的效果。本文根据本体图模型中属性序列的特点,综合考虑层次关系和属性关系,在分析路径关联相似度、层次相交关联相似度及属性相交关联相似度的影响因素的基础上给出了实例之间综合语义相似度的计算方法。文章最后讨论了该相似度计算方法在解决基于内容的推荐中的过于专门化问题、协同过滤推荐中的稀疏性问题以及检索中查全率和查准率问题中的应用。  相似文献   

20.
查新服务可以为科技成果的评审、鉴定、评奖、产业化等提供客观评价依据,必须作到公正、客观、准确,而文献资源的充足和全面是提高科技查新质量的基础,因此,科技成果查新信息源的建设与资源共享是一个亟待解决的课题。本文通过分析文献信息源在科技成果查新中的作用、类型、存在的问题,提出了相应的对策建议,并筒述了南京市科技信息研究所在科技成果查新信息源建设与共享中的实践和探索情况。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号