Search engines allow you to enter keywords or strings of keywords. Use this approach when you have unique words or are combining more than one idea. When using search engines it is important to translate question into search terms, use those search terms in strategic ways examining the resulting "hits," and then, if necessary, refine the search terms.
Search engines match words character-for-character. Though some engines are now including a subject directory as well, when using the functions of the search engine, remember that no human thought is involved on the other end: No one has classified the sites. For example, if you are looking for information on the human heart, you may not pick up web pages that use the synonym cardiac unless you search that term as well. American Library Association 1998