Search Engines require the user to construct the search by entering search terms into a search form. Many Search Engines offer simple and advanced searches, with various options for using Boolean Operators, truncation, search limitations, ranking, and result displays. Search Engines are best for more complex searches, specialized topics, and when comprehensive searches are desired.
In Standard Search Engines, you submit keywords to their individual database of web pages. You then receive a different display of documents from each Search Engine. Results from submitting very comparable searches can differ widely (about 40% unique content ), but also contain some of the same sites (about 60% overlap).
There are also Meta-Search Engines where you submit keywords in a search box and it transmits your search simultaneously to several individual search engines and their databases of web pages. Within a few seconds you receive results from all the search engines queried. Meta-Search Engines do not own a database of web pages; they send your search terms to databases maintained for other Search Engines.
Some Meta-Search Engines offer many useful secondary, portal-like services and unique collections of web sites and/or resources for businesses, web designers, movie goers, and other specialized interest groups. Others offer "pseudo meta-searching"--a collection of search boxes for different search engines or a drop-down menu that lets you choose which one from among a list of search engines to search.
Search protocol--the way you enter search keywords--is far from standardized. Almost all Search Engines accept " " as causing a phrase. A few accept the Boolean Operators AND, OR, and NOT. Fewer yet accept ( ) to group terms. While others only accept + or -. Some default to OR and others to AND. Some take * to truncate, and others stem automatically.
Other Search Engines are utilizing Natural Language Searches. You submit your search in ordinary language--How many goals did Pat LaFontaine score?--without the need for Boolean Operators or other specialized techniques.
Click the picture to learn to select a Search Engine.
Sample Standard Search Engines . . . 
Sample Meta-Search Engines . . .
Sample Natural
Language Search Engines . . .
Evaluate Your Search Engine
Click the picture to learn how to evaluate.
