29 Web Search Engines

Web search engines use special software programs (called robots, spiders, or crawlers) to find Web pages and list (or index) all words within each one to make searching large quantities of pages faster. Indexes capture the largest amount of information on the Web, but no index lists everything on the Internet.

Commonly used search engines include Google (https://www.google.com) and Bing (http://www.bing.com).

In addition to search engines, there are also:

• Specialized web search engines – A tool that has a specialty, usually either a subject or format focus. It ignores the rest of the information on the web. Examples include science.gov (http://www.science.gov/), TinEye Reverse Image Search (https://www.tineye.com), or a computational search engine like WolframAlpha (https://www.wolframalpha.com/)
• Metasearch engines – Tools that search multiple web search engines and gives you results from all of them. Some of these return the best results from the search engines they search. Examples include Dogpile (http://www.dogpile.com) and WebCrawler (https://www.webcrawler.com).
• Web directories – Tools created by editors or trained researchers who categorize or classify web sites by subject. Directories are more selective than search engines, such as Directory of Open Access Journals (http://doaj.org).

When to Use Them

Web Search Engines and related web search tools are helpful for locating background information, news (especially if it’s recent), and public opinion.

However, scholarly information is often not available through a regular web search. If you do find scholarly information through a web search engine, you may be asked for payment to access it. If you find a source not freely available, first check the library’s databases to see if you already have access to it. When it is not available from the library’s existing subscriptions, utilize the library’s Interlibrary Loan (ILL) service to obtain the source. The GHC Library has this service and is free-of-charge to students.

Remember to follow the advice on evaluating sources to determine whether information you locate online is suitable for your information needs.