A search on the Net is similar to a search on one of the computer legal search services. You type in a string of words and (hopefully) retrieve information you want. This column explains how search engines work and how to increase your chances of getting useful results.

A search engine works this way. The search engine uses a program called a "spider" to scan a portion of the Net, site-by-site. The information found is evaluated and catalogued. Each search engine looks for and evaluates the sites it scans by its own method.

Contrary to popular belief, no search engine covers the entire Net, or even the entire World Wide Web. Those with the largest databases cover perhaps 100 million sites. Some cover parts of the Web and FTP sites; a few include FTP and Usenet messages as well. Some search engines are quite specialized - for example, those which search only law-related information.

Because of the difference in coverage and in cataloging, no two search engines return the same results. Search engines also differ in the language permitted in search requests. Some search for any of the words listed in the request; others seek all of the words; still others permit the use of boolean connectors (such as "not") familiar to users of commercial legal search services. As a result, the differences in results can be quite dramatic: one may produce thousands of results, while another only a few, or even none.

That's why it's wise to keep bookmarks for several search engines. Use specialty search engines for law, Usenet or FTP if you are looking for a newsgroup message. If you are casting a broad net, use a search engine with a broad base or, better yet, a metasearch engine - a site that submits your request to several search engines. Oncebookmarked in your browser, you can view a menu of search engines and then go to the selected site with a click of the mouse.

A typical problem in conducting searches is that the results are too numerous. For example, a search engine might reply that "1,076 results match your query," and display them 20 or so at a time.

Here is how to address that problem. First, search results are generally hierarchical, with the "best" matches first. Sometimes the search engine reveals the degree of matching as a percentage, such as "93%," in the search results. Accordingly, you can view the first few pages of search results even though you leave most matches unread.

Second, you can try the "advanced search" option offered by many search engines. This option permits you to use boolean connectors for a more precise search than with mere "or" and "and" connectors. Search engines vary on what connectors are permitted, so try the "help" button they also usually offer.

Third, you can revise your original search request to add terms.

Fourth, try another search engine. There are perhaps 30 major search engines, and they vary in scope and cataloging methods. This strategy is also at the top of your list if you have too few results rather than too many.

Here are some specific search engine recommendations:

Dogpile is a metasearch site. It submits your single typed request to 12 other search engines and displays results at least two search engines at a time. This site excels because, unlike some other metasearch sites, you only have to type your request once and because it uses some of the best search engines. The Internet address (or URL) for Dogpile is www.dogpile.com. Runner up in the metasearch category: www.cyber411.com.

AltaVista is not only as comprehensive a site as any other search engine, but it is also very fast in returning results. Its biggest fault - returning an intimidatingly large number of results - can also be its biggest asset. If you are searching for something obscure and wish to use only a single search engine, start here. Altavista is one of the search engines used by Dogpile. Runners up: Hotbot (www.hotbot.com); Infoseek (www.infoseek.com); Lycos (www.lycos.com).

Yahoo is not, strictly speaking, a search engine; it is a directory. Although its base is much smaller than a search engine's the sites are selected by humans, not computers. Yahoo is the largest directory. URL: www.yahoo.com.

LawCrawler is arguably the best legal search engine. Boolean connectors are allowed, and the search can be limited to specific databases for international law, U.S. federal materials, state materials, law reviews, etc. The URL: www.lawcrawler.com.

If you need to search more than the Web, try Metacrawler.It searches both Usenet (newsgroups) and FTP (file transfer protocol) sites as well.

If you want a list of search engines, visit www.directoryguide.com. or members.home.net/sidebar/side links.htm.

Send your Internet questions and recommendations to: The Internet Browser, Arizona Attorney, 111 W. Monroe, Suite 1800, Phoenix AZ 85003-1742, or email:sidebar@home.net.