When beginning research on a health subject, you have three options:

		Use a search engine to search widely on the Internet.
		Use subject directories for health that provide links to selected health articles.
		Use a trusted source.

A search engine is automated and programmed to send out “robots” or “spiders” to jump from link to link to locate files posted on the Web (no search engine can find them all!) and index what it finds, ready to match them with keywords you enter. A subject directory—Yahoo! is the most well-known of these—employs people to varying degrees to categorize sites or select the most useful sites. Some directories specialize in health information. A search engine is likely to point you to more, broader information. . .a directory offers what the staff believes is the best information in a category.

Definition	Have three parts: Search term entry form Index Programs (spiders/robots)	Internet resources selected by people and organized by subject
Examples	AltaVista HotBot Google Lycos	Yahoo! HealthWeb Medical Matrix MedWeb
Good for...	Looking for something specific Searching widely on the web	Finding the best in a subject area Getting an idea of what's out there Looking for something general
Weaknesses	Thousands of results Results are not reviewed	Only a small selection of availiable resources May not be searchable by keyword

Source: Cushing/Whitney Medical Library at Yale

As search engines evolve, many seem to be adopting some of the positive features of directories. For example, a new feature in AltaVista is the option to browse through its “editor-selected sites.”

Using search engines
To do a search, enter one or more words that describe the information you seek in the search box present on every search engine’s home page. The words you use will greatly affect the type of information returned. Even the slightest change—such as capitalizing the first letter of the search word—can change the results of the search. One-word searches are a good way to start, but may turn up thousands of matches or links to Web sites.

Narrowing your search
Boolean searches—which really aren’t as hard to use as the name is to pronounce—provide a way to connect words and narrow your search.

Example: use AND, OR or NOT, such as: antidepressants NOT Paxil Example: for information on diagnosing ear infections, type in: diagnosing AND "ear infections" Be sure to capitalize the connecting word (AND) and put the words "ear infections" between quote marks. Quote marks tell the search engine to look for both words as a phrase, not separately.

	+cholesterol
		Using the + sign guarantees documents returned will include cholesterol
	smoking -passive
		Adding the - in front of the word passive excludes documents related to passive smoking
	smok*
		By using just the first few letters of common words followed by an asterisk, your search will turn up variant endings, such as smoke, smoker, smoking
	Use lower case letters. Only use capitalization if the word is usually capitalized.
	Consult Help for the best way to use a search engine. Not all engines support all of types of searches.

Spell correctly. An extra letter can change the meaning of the word (and the direction of the search). Spellex, a free online service, can help you spell those tough medical terms.