There are five general classes of tools that you can use to search for information. These are crawler-based search engines, meta-search tools, directories, subscription based services, and Medline search tools. Each has its own strengths and weaknesses.
- Crawler-based search engines more or less randomly index the Internet allowing you to search a broad range of web sites. They are not exhaustive.
- Metasearch tools send your search to several sites simultaneously and return the results together.
- Directories or metaindicies use a panel of editors to gather links to other web sites and group them according to content. They may provide their own internal search engine that searches only the sites to which they have pointers.
- Subscription based services are designed to be one-stop-shopping resources of reliable information for health care providers. These services will provide access to a variety of tools for a fee.
- Medline search engines allow searching of over 4600 biomedical journals. Carefully indexed but generally less current than the Web.