基于用户兴趣的PageRank算法改进策略

随着互联网海量信息的不断涌现,根据用户的兴趣提供相关查询结果,是现有搜索引擎要考虑的一个问题,PageRank算法是基于链接的排序算法,已在Google搜索引擎广泛应用,但其忽略了用户个性化需求。采用网页预分类技术,来表示用户查询的兴趣度,进一步提出改进传统的PageRank算法,从而能适当提高用户在使用搜索引擎方面的个性化需求。     

基于代理的多站点查询法在信息交易系统中的应用

在Internet上使用搜索引擎、门户网站、目录结构查询信息时有许多局限性，新近出现的查询方法对查询分布在不同站点上的数据也无能为力。该文介绍了一种根据用户需求进行查询并组合信息的平台及语言。     

低频查询的用户行为分析和类别研究

低频查询是用户提交查询频次非常低的查询.它们占了搜索引擎独立查询的很大比例且对用户体验影响巨大,但由于数据稀疏性,现有的搜索引擎用户行为分析及相关研究中对低频查询涉及很少.结合前人的相关工作,使用商业搜索引擎的大规模用户日志,在会话级别上进行低频查询的用户行为分析以及类别研究.基于目标查询行为、后续相关查询行为、整体会话行为3个方面的12个特征进行了低频查询的用户行为特征分析,首次提出了低频查询类别分析框架,并进一步使用改进的AdaBoost算法对低频查询会话进行分类.实验对2000个随机的低频查询会话样例进行分类,AUC值达到了83%以上.低频查询的用户行为分析和类别研究,将为搜索引擎用户行为分析等网络检索研究提供重要基础.     

网络搜索引擎的用户查询分析

利用教科网搜索引擎“网络指南针”的查询记录,就其中102439个用户的810396次查询,在用户查询方式、查询表达表达以及查询词3个层次上,对用户查询行为进行了分析,得到了搜索引擎用户查询的一般规律。根据上述结论对搜索引擎的进一步发展进行了讨论。     

论子话题粒度对搜索结果多样化算法的影响

随着生活节奏的加快,用户习惯将简短的查询提交给搜索引擎,并希望搜索引擎能体贴地将自己需要的结果返回在靠前的结果中。面对大量有歧义的或者意义广泛的查询,搜索引擎努力地识别用户意图,并试图用有限的结果取悦更多的用户。为了解决这个问题,搜索结果多样化技术应运而生,其任务是是对搜索结果进行重排序,在有限的搜索结果中满足尽可能多的用户意图。该文重点关注多样化算法中子话题的粒度问题。利用传统方法生成了不同粒度的子话题,并比较了使用不同粒度的子话题对搜索结果多样化算法的影响。实验结果表明,经典多样化算法使用细粒度的子话题时表现更好。     

个性化的社会标签查询扩展技术研究

随着互联网上的信息日益增长,个性化的搜索需求越来越迫切,由于用户兴趣的不同和行为的差异,如何为不同的用户提供不同的检索结果成为一个具有挑战性的问题。首先对现有搜索引擎的个性化信息检索和查询扩展技术进行了分类总结,分析了它们各自的优缺点。然后提出了基于社会化标签的个性化查询词扩展方法。这些方法通过从用户所收藏的社会化标签或标签所对应的网页中提取出和用户查询词相关的词,来对用户的初始查询进行扩展。最后利用Delicious网站上的用户数据,对比研究了这几种个性化查询扩展算法。通过与Google进行对比分析实验,结果表明所提出的社会化标签的个性化查询词扩展方法能够较好地满足用户的个性化需求,检索结果比Google的检索结果更接近用户需求。     

用户查询意图切分的研究

用户查询意图是指用户在构建查询时,希望搜索引擎能够返回的信息.如果搜索引擎可以判断用户当前查询与之前输入的查询是否属于同一查询意图,那么可以为用户提供更适当的查询建议、查询扩展或者个性化检索服务等.该文提出了基于点击相似度切分用户查询意图,在决策树模型和CRF模型上都取得了一定的提升.利用用户点击信息可以提高查询意图切分的效果,引入用户点击信息后,基于决策树的方法,F值提高1％,基于CRF模型的F值提高1.4％.     

搜索引擎的一种在线中文查询纠错方法

该文主要解决中文搜索引擎的查询纠错问题。错误的查询,已经偏离用户真实的搜索意图时,搜索质量很差,甚至导致搜索结果数为零。为此该文提出了一种服务于实际搜索引擎,较为完整的查询纠错方案。该文重点描述了纠错查询候选生成、纠错查询候选评价、以及基于核函数,挑选最优纠错查询候选等内容。通过在开放测试集上的准确率/召回率验证,以及在搜索引擎中实际的DCG评测,该文的方案都取得了较好的效果。     

基于Cranfield体系对中文搜索引擎性能的比较研究

本文通过应用Cranfield体系——构建查询样例集合、查询信息需求分类、抓取搜索引擎结果、规定标注准则、计算性能评价指标的基本流程,对目前常用中文搜索引擎,百度、谷歌、搜狗、搜搜、人民搜索性能从定量的角度,进行较为全面的评价。其结果可供用户在选择、利用这些搜索引擎时参考。     

一种基于查询特性的查询结果缓存与预取方法

针对搜索引擎查询结果缓存与预取问题,该文提出了一种基于查询特性的搜索引擎查询结果缓存与预取方法,该方法包括用来指导预取的查询结果页码预测模型和缓存与预取算法框架,用于提高搜索引擎系统性能。通过对国内某著名中文商业搜索引擎的某段时间的用户查询日志分析得出,用户对不同查询返回的查询结果所浏览的页数具有显著的非均衡性,结合该特性设计查询结果页码预测模型来进行预取和分区缓存。在该搜索引擎两个月的大规模真实用户查询日志上的实验结果表明,与传统的方法相比,该方法可以获得3.5%~8.45%的缓存命中率提升。     

基于逐点互信息的查询结构分析

Web搜索引擎中,对用户查询结构的有效分析,能更好地理解用户的查询意图,促进检索效果的提升。该文提出了一种简单高效的基于逐点互信息的查询结构分析方法,该方法包含了基于MapReduce的离线训练算法,以及一种自下向上的在线查询树构建算法。实验显示,该方法具有很高的切分速度,并能取得不错的可比较的切分效果。进一步的,该方法对检索性能的提升,也有明显的促进作用,在MAP,p@5,p@10评价指标上,都取得了不错的性能提升。     

融合多类特征的Web查询意图识别

识别搜索引擎用户的查询意图在信息检索领域是备受关注的研究内容。文中提出一种融合多类特征识别Web查询意图的方法。将Web查询意图识别作为一个分类问题,并从不同类型的资源包括查询文本、搜索引擎返回内容及Web查询日志中抽取出有效的分类特征。在人工标注的真实Web查询语料上采用文中方法进行查询意图识别实验,实验结果显示文中采用的各类特征对于提高查询意图识别的效果皆有一定帮助,综合使用这些特征进行查询意图识别,88。5%的测试查询获得准确的意图识别结果。     

A personalized query expansion approach for engineering document retrieval

Engineers create engineering documents with their own terminologies, and want to search existing engineering documents quickly and accurately during a product development process. Keyword-based search methods have been widely used due to their ease of use, but their search accuracy has been often problematic because of the semantic ambiguity of terminologies in engineering documents and queries. The semantic ambiguity can be alleviated by using a domain ontology. Also, if queries are expanded to incorporate the engineer’s personalized information needs, the accuracy of the search result would be improved. Therefore, we propose a framework to search engineering documents with less semantic ambiguity and more focus on each engineer’s personalized information needs. The framework includes four processes: (1) developing a domain ontology, (2) indexing engineering documents, (3) learning user profiles, and (4) performing personalized query expansion and retrieval. A domain ontology is developed based on product structure information and engineering documents. Using the domain ontology, terminologies in documents are disambiguated and indexed. Also, a user profile is generated from the domain ontology. By user profile learning, user’s interests are captured from the relevant documents. During a personalized query expansion process, the learned user profile is used to reflect user’s interests. Simultaneously, user’s searching intent, which is implicitly inferred from the user’s task context, is also considered. To retrieve relevant documents, an expanded query in which both user’s interests and intents are reflected is then matched against the document collection. The experimental results show that the proposed approach can substantially outperform both the keyword-based approach and the existing query expansion method in retrieving engineering documents. Reflecting a user’s information needs precisely has been identified to be the most important factor underlying this notable improvement.     

Modeling multiple interactions with a Markov random field in query expansion for session search

How to automatically understand and answer users' questions (eg, queries issued to a search engine) expressed with natural language has become an important yet difficult problem across the research fields of information retrieval and artificial intelligence. In a typical interactive Web search scenario, namely, session search, to obtain relevant information, the user usually interacts with the search engine for several rounds in the forms of, eg, query reformulations, clicks, and skips. These interactions are usually mixed and intertwined with each other in a complex way. For the ideal goal, an intelligent search engine can be seen as an artificial intelligence agent that is able to infer what information the user needs from these interactions. However, there still exists a big gap between the current state of the art and this goal. In this paper, in order to bridge the gap, we propose a Markov random field–based approach to capture dependence relations among interactions, queries, and clicked documents for automatic query expansion (as a way of inferring the information needs of the user). An extensive empirical evaluation is conducted on large‐scale web search data sets, and the results demonstrate the effectiveness of our proposed models.     

一种个性化查询扩展方法

针对当前主流web搜索引擎存在信息检索个性化效果差和信息检索的精确率低等缺点, 通过对已有方法的技术改进, 介绍了一种基于用户历史兴趣网页和历史查询词相结合的个性化查询扩展方法。当用户在搜索引擎上输入查询词时,能根据学习到的当前用户兴趣模型动态判定用户潜在兴趣和计算词间相关度,并将恰当的扩展查询词组提交给搜索引擎,从而实现不同用户输入同一查询词能返回不同检索结果的目的。实验验证了算法的有效性,检索精确率也比原方法有明显提高。     

A Knowledge-Based Approach to Effective Document Retrieval

This paper presents a knowledge-based approach to effective document retrieval. This approach is based on a dual document model that consists of a document type hierarchy and a folder organization. A predicate-based document query language is proposed to enable users to precisely and accurately specify the search criteria and their knowledge about the documents to be retrieved. A guided search tool is developed as an intelligent natural language oriented user interface to assist users formulating queries. Supported by an intelligent question generator, an inference engine, a question base, and a predicate-based query composer, the guided search collects the most important information known to the user to retrieve the documents that satisfy users' particular interests. A knowledge-based query processing and search engine is devised as the core component in this approach. Algorithms are developed for the search engine to effectively and efficiently retrieve the documents that match the query.     

Impact of query intent and search context on clickthrough behavior in sponsored search

Implicit feedback techniques may be used for query intent detection, taking advantage of user behavior to understand their interests and preferences. In sponsored search, a primary concern is the user’s interest in purchasing or utilizing a commercial service, or what is called online commercial intent. In this paper, we develop a methodology for employing the content of search engine result pages (SERPs), along with the information obtained from query strings, to study characteristics of query intent, with a particular focus on sponsored search. Our work represents a step toward the development and evaluation of an ontology for commercial search, considering queries that reference specific products, brands, and retailers. Characteristics of query categories are studied with respect to aggregated user clickthrough behavior on advertising links. We present a model for clickthrough behavior that considers the influence of such factors as the location of ads and the rank of ads, along with query category. We evaluate our work using a large corpus of clickthrough data obtained from a major commercial search engine. In addition, the impact of query intent is studied on clickthrough rate, where a baseline model and the query intent model are compared for the purpose of calculating an expected ad clickthrough rate. Our findings suggest that query-based features, along with the content of SERPs, are effective in detecting query intent. Factors such as query category, the rank of an ad, and the total number of ads displayed on a result page relate to the context of the ad, rather than its content. We demonstrate that these context-related factors can have a major influence on expected clickthrough rate, suggesting that these factors should be taken into consideration when the performance of an ad is evaluated.     

基于语义查询扩展的垂直搜索研究

基于关键词的搜索引擎无法满足用户需求,传统查询扩展方式又会带来许多语义理解错误,针对该问题,提出一种基于本体的垂直搜索引擎概念模型,建立基于关键词和基于概念的两层索引结构,利用行业领域本体对用户提交的关键词进行语义查询扩展,并对按照本体标注的文档进行排序优化,提高查询的查全率和查准率。