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1.
随着互联网的不断发展,搜索引擎现在已成为网络用户获取信息的一个不可或缺的检索工具。就搜索引擎的概念、评价指标及检索机制、分类、各种搜索引擎的比较以及它在网络信息检索中的作用进行了介绍。 相似文献
2.
随着互联网的不断发展,搜索引擎现在已成为网络用户获取信息的一个不可或缺的检索工具.搜索引擎目前存在诸多问题,例如查全率和查准率、功能问题、作弊问题、安全性问题、信息更新问题、规范化问题等.本文就这些问题进行一些探讨. 相似文献
3.
利用知识搜索唤起并挖掘用户探索未知的热情,反作用于探索频道本身的建设与发展,这种相互促进的合作模式被广为看好搜索引擎现在已成为网民获取信息的必备工具,但是,仅凭几个关键字词,即便是对熟练操作使用搜索引擎的人来说,搜索结果的满足使用率也非常有限。 相似文献
4.
随着互联网信息量的急剧膨胀,搜索引擎逐渐成为人们获取信息的重要途径.为迎合这一趋势,百度推出的框计算的核心在于准确识别用户需求,提高搜索引擎的响应速度和结果的准确度.然而,随着用户需求的日益复杂和多样化,如何满足其个性化需求是框计算研究的重点和难点之一.针对此问题,提出了一种基于浏览行为的用户聚类方法,并结合框计算精准性制约因素设计了一种改进的框计算模型. 相似文献
5.
近年来,越来越多的用户获取信息资源都是依赖于搜索引擎,在搜索引擎给人们提供巨大的信息获取便利性的同时,其安全性也正面临着严峻的考验.本文首先对搜索引擎在网络层、连接层和应用层会遭遇的典型的黑客攻击手段的细化总结,分析了如今搜索引擎的安全性需求,给出了搜索引擎防攻击体系的结构模型,以此来为搜索引擎安全性的建设和规划提供理论参考. 相似文献
6.
垂直搜索引擎在获取信息方面有着综合搜索引擎无法比拟的优势,在B2B领域中垂直搜索引擎开始成为搜索引擎发展的一个新趋势。研究了B2B垂直搜索引擎在信息获取技术中与其他搜索引擎的区别,探索了垂直搜索引擎在信息获取技术中应用的价值,并对B2B垂直搜索引擎在信息技术中的应用进行了展望。 相似文献
7.
以荷兰大学学生网上信息检索调查为例，通过分析研究认为各种不同层次的用户在使用搜索引擎、浏览器、查找网站等情况下获取信息所采取的方法、途径不同。 相似文献
8.
从用户角度评价网络搜索引擎 总被引：3，自引：0，他引：3
随着互联网的广泛应用,搜索引擎成为了越来越多的用户从海量信息中获取知识必不可少的工具,利用哪些搜索引擎以及怎样利用它们才能获得更多、更准确的信息成为网络用户所关心的问题。本文试从网络用户的角度介绍、分析和讨论互联网搜索引擎,结合历史和现状具体讨论了查全率和查准率以及相关性问题,从选择搜索引擎、使用搜索引擎、认识搜索结果和用户负担几个方面建立评价标准。 相似文献
9.
以Google为代表的搜索引擎和以Yahoo!为代表的网站目录是目前互联网用户获取信息的基本方式。本文从互联网的出现及网络信息检索的历史出发，通过对搜索引擎和网站目录在基本设计思想、商业化影响等方面的分析．尝试提出了一种新的网络检索系统的构想。 相似文献
10.
搜索引擎已经渗透到了我们的生活之中,是我们获取信息的重要途径。因此它对我们的影响也在逐步扩大。而随着网络的发展,人们对互联网的需求也越来越高。就是这样高需求的环境也为搜索引擎的进步带来一个难度更大的挑战,这些挑战来自各方各面,要想获得成功并不是一件简单的事情。本文将简单的阐述一下搜索引擎未来发展所面临的问题进行了剖析,对于搜索引擎的优化则重在讲解用户体验的必要性。 相似文献
11.
With ever increasing information being available to the end users, search engines have become the most powerful tools for obtaining useful information scattered on the Web. However, it is very common that even most renowned search engines return result sets with not so useful pages to the user. Research on semantic search aims to improve traditional information search and retrieval methods where the basic relevance criteria rely primarily on the presence of query keywords within the returned pages. This work is an attempt to explore different relevancy ranking approaches based on semantics which are considered appropriate for the retrieval of relevant information. In this paper, various pilot projects and their corresponding outcomes have been investigated based on methodologies adopted and their most distinctive characteristics towards ranking. An overview of selected approaches and their comparison by means of the classification criteria has been presented. With the help of this comparison, some common concepts and outstanding features have been identified. 相似文献
12.
Web search engines are beginning to offer access to multimedia searching, including audio, video and image searching. In this paper we report findings from a study examining the state of multimedia search functionality on major general and specialized Web search engines. We investigated 102 Web search engines to examine: (1) how many Web search engines offer multimedia searching, (2) the type of multimedia search functionality and methods offered, such as “query by example”, and (3) the supports for personalization or customization which are accessible as advanced search. Findings include: (1) few major Web search engines offer multimedia searching and (2) multimedia Web search functionality is generally limited. Our findings show that despite the increasing level of interest in multimedia Web search, those few Web search engines offering multimedia Web search, provide limited multimedia search functionality. Keywords are still the only means of multimedia retrieval, while other methods such as “query by example” are offered by less than 1% of Web search engines examined. 相似文献
13.
在浩瀚如海的网络世界里,信息资源犹如海洋生物,大大小小,无孔不入,如何能够快速而准确地找到并获取自己所需的信息,成为我们这个时代最需解决的根本问题之一。当然,利用各种搜索引擎可以查找到很多信息资源,但是也有一些信息通过搜索引擎是无法找到的,它们隐藏在这个网络世界的某个角落,因为某种原因而不为大多人所熟知,但是这些信息本身却有着很高的使用价值。美国的Sherman·C等人把这些资源命名为"看不见的网站(Invisible—web)"。"看不见的网站"里拥有信息检索人员难以置信的有价值的资源。本文阐述了"看不见的网站"的含义及价值,指出信息检索人员应该如何有效利用"看不见的网站"资源,最后提供一些查找"看不见网站"的途径与工具。 相似文献
14.
网上经济信息资源分布及检索策略研究 总被引：7，自引：0，他引：7
网上信息资源包括 :电子期刊资源、图书信息、报纸资源、学位论文资源、网上政府信息等。检索的方法有很多 ,可直接进入网站或数据库、利用搜索引擎、利用专业信息资源导航系统获取信息资源。 相似文献
15.
Comparing rankings of search results on the Web 总被引：1，自引：0，他引：1
The Web has become an information source for professional data gathering. Because of the vast amounts of information on almost all topics, one cannot systematically go over the whole set of results, and therefore must rely on the ordering of the results by the search engine. It is well known that search engines on the Web have low overlap in terms of coverage. In this study we measure how similar are the rankings of search engines on the overlapping results.We compare rankings of results for identical queries retrieved from several search engines. The method is based only on the set of URLs that appear in the answer sets of the engines being compared. For comparing the similarity of rankings of two search engines, the Spearman correlation coefficient is computed. When comparing more than two sets Kendall’s W is used. These are well-known measures and the statistical significance of the results can be computed. The methods are demonstrated on a set of 15 queries that were submitted to four large Web search engines. The findings indicate that the large public search engines on the Web employ considerably different ranking algorithms. 相似文献
16.
Laura A. Granka 《The Information Society》2013,29(5):364-374
In “Shaping the Web: Why the Politics of Search Engines Matters,” Introna and Nissenbaum (2000) introduced scholars to the political, as well as technical, issues central to the development of online search engines. Since that time, scholars have critically evaluated the role that search engines play in structuring the scope of online information access for the rest of society, with an emphasis on the implications for a democratic and diverse Web. This article describes the thought behind search engine regulation, online diversity, and information bias, and it places these issues within the context of the technical and societal changes that have occurred in the online search industry. The author assesses which of the initial concerns expressed about online search engines remain relevant today and discusses how technical changes demand a new approach to measuring online diversity and democracy. The author concludes with a proposal to direct the research and thought in online search going forward. 相似文献
17.
《Information processing & management》2019,56(5):1753-1770
XML has become a universal standard for information exchange over the Web due to features such as simple syntax and extensibility. Processing queries over these documents has been the focus of several research groups. In fact, there is broad literature in efficient XML query processing which explore indexes, fragmentation techniques, etc. However, for answering complex queries, existing approaches mainly analyze information that is explicitly defined in the XML document. A few work investigate the use of Prolog to increase the query possibilities, allowing inference over the data content. This can cause a significant increase in the query possibilities and expressive power, allowing access to non-obvious information. However, this requires translating the XML documents into Prolog facts. But for regular queries (which do not require inference), is this a good alternative? What kind of queries could benefit from the Prolog translation? Can we always use Prolog engines to execute XML queries in an efficient way? There are many questions involved in adopting an alternative approach to run XML queries. In this work, we investigate this matter by translating XML queries into Prolog queries and comparing the query processing times using Prolog and native XML engines. Our work contributes by providing a set of heuristics that helps users to decide when to use Prolog engines to process a given XML query. In summary, our results show that queries that search elements by a key value or by its position (simple search) are more efficient when run in Prolog than in native XML engines. Also, queries over large datasets, or that searches for substrings perform better when run by native XML engines. 相似文献
18.
《Information processing & management》2004,40(4):693-707
Commercial search engines are now playing an increasingly important role in Web information dissemination and access. Of particular interest to business and national governments is whether the big engines have coverage biased towards the US or other countries. In our study we tested for national biases in three major search engines and found significant differences in their coverage of commercial Web sites. The US sites were much better covered than the others in the study: sites from China, Taiwan and Singapore. We then examined the possible technical causes of the differences and found that the language of a site does not affect its coverage by search engines. However, the visibility of a site, measured by the number of links to it, affects its chance to be covered by search engines. We conclude that the coverage bias does exist but this is due not to deliberate choices of the search engines but occurs as a natural result of cumulative advantage effects of US sites on the Web. Nevertheless, the bias remains a cause for international concern. 相似文献
19.
国内医学搜索引擎的现状及发展对策 总被引：1，自引：0，他引：1
通用搜索引擎没有对医学专业信息进行优化处理，不适合检索专业化的医学信息。因此，为了适应用户需要，加强对医学专业搜索引擎的研究是十分必要的。本文指出了国内医学搜索引擎存在的问题，提出了中文医学搜索引擎改变现状、快速发展的几点对策。 相似文献
20.
《Information processing & management》1999,35(3):337-362
There was a proliferation of electronic information sources and search engines in the 1990s. Many of these information sources became available through the ubiquitous interface of the Web browser. Diverse information sources became accessible to information professionals and casual end users alike. Much of the information was also hyperlinked, so that information could be explored by browsing as well as searching. While vast amounts of information were now just a few keystrokes and mouseclicks away, as the choices multiplied, so did the complexity of choosing where and how to look for the electronic information. Much of the complexity in information exploration at the turn of the twenty-first century arose because there was no common cataloguing and control system across the various electronic information sources. In addition, the many search engines available differed widely in terms of their domain coverage, query methods and efficiency.Meta-search engines were developed to improve search performance by querying multiple search engines at once. In principle, meta-search engines could greatly simplify the search for electronic information by selecting a subset of first-level search engines and digital libraries to submit a query to based on the characteristics of the user, the query/topic, and the search strategy. This selection would be guided by diagnostic knowledge about which of the first-level search engines works best under what circumstances. Programmatic research is required to develop this diagnostic knowledge about first-level search engine performance.This paper introduces an evaluative framework for this type of research and illustrates its use in two experiments. The experimental results obtained are used to characterize some properties of leading search engines (as of 1998). Significant interactions were observed between search engine and two other factors (time of day and Web domain). These findings supplement those of earlier studies, providing preliminary information about the complex relationship between search engine functionality and performance in different contexts. While the specific results obtained represent a time-dependent snapshot of search engine performance in 1998, the evaluative framework proposed should be generally applicable in the future. 相似文献