What are search engines, when should I use them and what are their limitations?

Search Engines are tools that allow the user to perform keyword searches to locate Web sites on various topics. They use electronic ‘robots’ or ‘spiders’ which ‘crawl’ through millions of Web sites at a given time in order to create large catalogs or databases of Web pages. Thus, when using a search engine, the user is NOT searching the entire Web ‘live’, but rather a collection of sites that has been compiled previous to your search. These large databases of Web sites are keyword searchable. They're best for researching specific pieces of information or facts.

When Should I Use A Search Engine

• When you need to locate a specific piece of information or a known document rather than a general subject (e.g. the State of Wisconsin Web page)
• When you want to take advantage of certain unique search engine features like relevance ranking, clustering, etc.

Examples of Search Engines

• Google (http://www.google.com)
• AltaVista (http://www.altavista.com)
• Excite (http://www.excite.com/search)
• FAST (http://www.alltheweb.com)
• HotBot (http://hotbot.lycos.com)
• Northern Light (http://www.northernlight.com)

It may seem that all search engines perform the same way; however, each one is actually organized and works slightly differently. This is the reason why you may retrieve extremely different results depending on what search engine you use. Factors that influence the amount of results you retrieve include:

• the size of the engine’s collection of web pages
• how often new web sites are added and updated
• the capabilities and features of the search engine

Search engines also differ in their search speed, the design of the search interface, the way in which they display results, and the amount of help they offer to users. To be successful, be sure to take some time to learn some of the basic or advanced search features that are available in the search preferences and help screens.

A comparison of search engines and helpful search tips can be found at the Search Engine Watch Web site (http://searchenginewatch.com/).

Limitations of Search Engines

• No organizational control (No subject headings or thesaurus terms in place)
• You often must sort through extremely large search results
• You may get more college course listings than useful information…other seemingly good items that are really off-track from your needs
• Information normally found via a search engine has not been through a peer review process - it's not often ‘scholarly’ or academic information

What are Subject Directories and when should I use them?