What is a search engine and how does it work?

A search engine is the most common tool used to locate information on the Web. Yahoo! and Google are just two examples of search engines that have been created to meet the demand for quickly finding information.

Search Queries
Search engines allow users to enter search terms known as keywords, which can be either words or phrases. The act of conducting a keyword search is called a search query. Example: Imagine you are looking for information on Albert Einstein. You can type his name into the search field of one of these engines. The search engine will scan a database for the keywords Albert Einstein and locate any Web pages that contain these words. Then the search engine will compile the relevant pages and generate a list of their URLs.

Below is the home page from Google's search engine. Notice the keyword function, advanced search, and directory options provided for easy searching and browsing.

Search Results

It's important to know that not all search engines deliver the same results.

• First of all, different engines search different databases for the information you specify in your search query. Some databases are more sophisticated and more detailed than others.
  
  
• Secondly, the organization of search results varies, depending on the search engine you are using. Generally, the results at the top of the page are what the search engine interprets as the most relevant to your search. However, not all search engines measure relevancy in the same way. For example, with many search engines, a Web page will have a higher ranking in the list of results if your keywords appear many times throughout the Web page—in the title, near the beginning, or close together on the page.

For these reasons, you should never rely on just one search engine when you're conducting research on the Web. Try using more than one engine; doing so will likely yield better, richer results!

What is a meta-search engine?

A meta-search engine scans multiple search engines simultaneously and provides results based on the keyword(s) submitted. Meta-search engines can save time, but it's best not to rely on them exclusively. Since search engines interpret search terms differently, one or more of them might misunderstand your keyword(s). Before using a meta-search engine, find out how it compiles results. This information usually appears on a site's Help page.

Vivísimo is a meta-search engine that allows users to search the Web or specific sites such as MSN™ and Lycos ®. Be aware that Vivísimo only searches URLs, titles, and descriptions from other search engines' results pages and not the actual Web sites themselves. Vivísimo also features a new technology called a clustering engine, which organizes search results into categories.

Refining your Search

Not getting the results you expected from a search engine? One simple step you can take is to make changes to your search query. Try using different modifiers, phrases, or synonyms to make your query even more specific.

In addition, you might read the Help or Search Tips page of each search engine to help you refine your search. These features guide you on how to use advanced search techniques. One common type of advanced search is called a Boolean search. With Boolean searches, you can increase the accuracy of your searches by specifying the relationships among keywords and phrases. The most commonly used Boolean operators include AND, OR, and NOT.

Boolean Searches at a Glance

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Adapted from: Houghton Mifflin Company. 2006