8.1.1 Navigation Service Algorithms and Operations

Efforts to improve Internet navigation services1 are being undertaken in several areas that include:

  • Increasing the amount of material indexed and the frequency of indexing.2 This is a topic of competitive research and development among commercial search services and is dependent primarily on the available computing and storage capacities. Most of the effort goes into increasing the computing capabilities and storage facilities deployed. There is also a trade-off between the size of the computational resources and the depth to which sites are searched.

  • Improving algorithms for matching requests with results.3 Commercial search services devote substantial effort to improving these algorithms, and there is a large and vibrant community studying them in academic and other research institutions.4

  • Delimiting and describing specific regions of search. In many cases, users wish to limit the scope of their search. For example, searches may be limited to a particular site or Uniform Resource Locator (URL), to definitions, to telephone numbers, to a range of dates, to specific locations, and to a number of other special regions. Many other categories could be used to limit or filter results (e.g., a person, a book, an article).

  • Autonomous collection of information by search agents. Software agents5 to automate access to information have long been predicted. Research efforts continue to look for ways to use agents automatically to aggregate news and information based on a person’s interests. Some of


For an overview of research on information retrieval that underlies much of Internet navigation technology, see Ricardo Baeza-Yates and Berthier Ribeiro-Neto, Modern Information Retrieval, Addison-Wesley, Wokingham, U.K., 1999.


See, for example, Baeza-Yates and Ribeiro-Neto, Chapter 8, “Indexing and Searching,” written with Gonzalo Navarro, in Modern Information Retrieval, 1999.


See, for example, Baeza-Yates and Ribeiro-Neto, Chapter 5, in Modern Information Retrieval, 1999.


For example, see Michael Kanellos, “Next Generation Search Tools to Refine Results,” Techrepublic.com, August 9, 2004, available at <http://techrepublic.com.com/5100-22_11-5302095.html>. In addition, the considerable worldwide research activity is reported in conferences and publications sponsored by TREC (Text Retrieval Conference), which is supported by the National Institute of Standards and Technology and the Department of Defense, and the Special Interest Group on Information Retrieval (SIGIR) of the Association for Computing Machinery (ACM). Information on TREC can be found at <http://trec.nist.gov>. Information on SIGIR can be found at <http://www.acm.org/sigir>.


According to the Dublin Core Metadata Glossary, “A computer program that carries out tasks on behalf of another entity. Frequently used to reference a program that searches the Internet for information meeting the specified requirements of an individual user.” The Dublin Core Web site is at <fttp://www.purl.org/dc/>.

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