Search Engine

A search engine refers to a tool used by computers to find information. Modern search engines typically employ graphic interfaces. The term search engine is closely associated with the tool used to search for information on the World Wide Web. Any graphic-search interface such as those used by universities and public libraries to search for books, magazines, multimedia documents, and so forth can be called a search engine. Without the search engine, it would not be possible to locate specific information from among the billions of unique Web pages that currently exist on the World Wide Web (Kent, 2001).

Search engines work by examining archival databases generated from the billions of Web sites currently accessible. Search engines use an assortment of indexing logics. Most search engines create indexes based on keywords, phrases, categories, and other heuristics. Many search engines also allow users to employ real language. Ask Jeeves, for example, lets users phrase their searches as actual questions rather than a collection of keywords. Other search engines, such as Google, employ networking logic, ranking pages by their connectedness to other Web sites. The more popular a page is, the more likely it is to rise to the top of Google's list.

When searching the Web, most search engines allow users to employ (a) Boolean logic (AND, OR, NOT), (b) phrase searches (surrounding words with quotation marks), (c) wildcard searches (replacing prefixes/suffixes with an ∗), and (d) nested searching (complex searches created by using parentheses and [Page 769]algebraic logic). Because search features vary from search engine to search engine, users are encouraged to learn the particular features supported by their preferred search engines.

Suggestions for effective Web searching include

• 1.
  Use multiple keywords—sometimes a dozen or more.
• 2.
  Search for phrases (“words in quotes”), especially with names, whenever possible.
• 3.
  Rare or unusual words such as defenestrate make it easier to narrow results.
• 4.
  Common works such as computer make it difficult to narrow results.
• 5.
  Order search terms from most important to least important.
• 6.
  Do not waste time searching through large lists of hits—more success will result by adding new search terms or rephrasing the search by adding quotation marks.

There are currently hundreds of search engines available for use on the World Wide Web. Notable search engines include AltaVista, Ask Jeeves, Google, Ixquick, Lycos, Mamma, and Yahoo.