Meta-search engines are useful for quick, simple, uncomplicated searches. These engines provide a compilation of results by search engine.

Becoming familiar with the search features used by the various search engines is as important as choosing a search engine. Some provide Boolean searching using the operators AND, OR, NOT; others provide symbols such as +, -, or | to obtain similar results. Search tool features such as expanding a search using truncation symbols, or limiting by year, domain, language, etc. are also available among the various search engines. Familiarity with these features will allow you to develop effective searching strategies that will provide you with relevant information and less frustration.


Boolean searching

In order to broaden or narrow a search, you can use AND, OR and NOT. For example, if you want information on infectious diseases, topics in this area may also be found under communicable diseases. A vast amount of information may be overlooked or duplicated if you search each term individually. However, searching (infectious OR communicable) and diseases using boolean operators broadens your search to retrieve sites that have either infectious or communicable and diseases, thus satisfying all criteria.

If you have an interest in infectious diseases in China, then using the AND operator will limit the search to only those sites that include both infectious diseases and China. Use of quotation marks can be critical depending on the search engine.


What is an effective search strategy?

The goal is to obtain relevant, reliable sites without being overwhelmed by too many hits. Searching for a simple term or phrase with an active search engine often leads to many irrelevant hits. You may want to start out using a subject directory search engine, move to an active search engine, and then incorporate Boolean searching or the engine's particular searching features to refine your search.