Medical Information on the Internet

Medical Librarians

Web Search Engines Objectives Terminology Know Your Choices Directories Search Engine Metasearch Evaluating Your Results

PubMed/NLM Gateway

Clinical Trials

Books/Journals

Consumer Health

Statistics

Doctors/Hospitals

Drug Information

Genetic Information

Historical Information

Learning More

Evaluation

Know Your Choices

The number of search engines available on the Web changes daily. In order to effectively search the Web, select a few search sites and become familiar with their search features. You want to know if the Website is:

1. A directory
2. A search engine
3. A metasearch

You also want to know if the search engine:

1. Can do a Boolean search (clear instructions on Boolean logic available at <http://www.apa.org/psycinfo/training/boolean.html> and <http://www.boolistic.com/>; links open new windows)
2. Can truncate (for example, search for glossary or glossaries by just searching the root glossary)
3. Is case sensitive (knows the difference between AIDS and aids)
4. Can search for phrases

There are essentially three types of search engine, each presenting certain benefits as well as a number of drawbacks.

Types of Search Engines: Directory

The first type, the directory, represented by Yahoo and Open Directory (links open new windows), organizes links into categories and subcategories, which the searcher can access by either following the directory structure to the appropriate category, or by doing a simple search of their database. The advantage of the directory format is the ability to find a specific subject and examine a number of links on that topic. The disadvantage is that Websites are generally placed in only one category, even though a number of issues may be addressed by the page. (Sample Search: In Yahoo: AIDS, link to appropriate information by selecting Diseases and Condition>AIDS/HIV)