Transcript Document
Search Strategies Search Strategies Upon completion of this unit: Participants will be able to conduct a search using a single thread search engine. –Participants will be able to conduct a search using a multisearch engine. –Participants will be able to conduct a search using a subject guide. –Participants will utilize a variety of search strategies and search logic. Search Strategies This unit will explore the world’s largest library, the Internet. The books in this library have no covers. There is no title page and they are in no particular order. What will you do to find what you need in this chaos? Search Strategies There are many search tools out there to help you find your way on the World Wide Web. These tools include: –search engines –multi-threaded search engines (“meta” search engines) – subject specific search engines –subject guides. Search Strategies Search Engines A program that attempts to return relevant URL’s on information requested Search Strategies Search Engines Search Engines catalog web pages by keywords and store this information in a database that can be accessed through a URL. Search Engines •Bot – Short for robot. A program that accesses web sites to gather information for search engines. •Spider – A type of Bot that usually visits many sites at the same time. Its “legs” spanning out over a large part of the “Web” simultaneously •WebCrawler – A type of Bot that “crawls” through a site a page at a time. Search Engines Examples of Sites Alta Vista Excite HotBot Infoseek Northern Light www.altavista.com www.excite.com www.hotbot.com www.infoseek.com www.northernlight.com Search Strategies Multi-Threaded Search Engines A program that searches many search engines at the same time and attempts to return relevant URL’s on the information requested Search Strategies Multi-Threaded Search Engines There are so many single database search engines out there now that we have the capability to search many single database search engines at once by using a MultiThreaded Search Engine. Search Strategies Multi-Threaded Search Engines Examples of Sites Dogpile www.dogpile.com Inference www.infind.com Metacrawler www.go2net.com/search.html ProFusion www.profusion.com Search Strategies Subject Specific Search Engines Programs that search only a specific subject and attempts to return relevant URL’s on the information requested Search Strategies Subject Specific Search Engines Subject Specific Search Engines do not attempt to search the entire Web; instead they focus on depth of coverage within a certain subject. Subject Specific Search Engines EXAMPLES OF SITES Beaucoup! The Big Hub www.beaucoup.com www.thebighub.com Search Strategies Subject Guides A list of web sites by subject that can be browsed in search of relevant URL’s Subject Guides A subject guide is an organized index of subjects that can be browsed for relevant information. Subject guides are compiled and maintained by humans. As a result, the probability of receiving results that are out of context are greatly reduced. Subject guides work best when searching for a general piece of information rather than something more specific. Subject Guides Example of Sites Galaxy www.einet.net LookSmart www.looksmart.com Magellan magellan.excite.com Yahoo www.yahoo.com Search Strategies Preparing Search Logic Boolean logic is the operation that is used to combine search terms to explore many databases. This method requires use of certain acceptable terms in order to locate the appropriate information. Search Strategies Boolean Logic The acceptable terms or Boolean operators include AND, OR and NOT. Certain search engines also allow use of proximity operators including ADJACENT, NEAR and FOLLOWED BY. These terms would be typed in the search bar along with the topics desired. Search Strategies Boolean Operators Travel AND Auction Search Strategies Boolean Operators Travel OR Auction Search Strategies Boolean Operators Travel NOT Auction Search Strategies Are the results RELEVANT? Search engines return results with a total number of hits and a relevancy or confidence ranking. Therefore, sites listed at the top of the return list are the ones the search engine thinks best match the request. Most search engines use search term frequency to determine the relevancy ranking. The search engine assumes that if the term requested appears many times in a particular site that it is a high match for the request. Search Strategies On Your Own