Typically, Web search engines work by sending out a spider to fetch as many documents as possible. Another program, called an indexer, then reads these documents and creates an index based on the words contained in each document. Each search engine uses a proprietary algorithm to create its indices such that, ideally, only meaningful results are returned for each query. Sites that let you search multiple indexes simultaneously include: •Yahoo (http://www.yahoo.com)
Yahoo first searches its own hierarchically-structured subject directory and gives you those entries. Then, it provides a few entries from the AltaVista search engine. It also launches a concurrent search for entries matching your search argument with six or seven other major search engines. You can link to each of them from Yahoo (at the bottom of the search result page) to see what the results were from each of these search engines. A significant advantage of a Yahoo search is that if you locate an entry in Yahoo, it's likely to lead you to a Web site or entire categories of sites related to your search argument. A search.com search primarily searches the Infoseek index first but also lets you search the other major search engines as well. EasySearcher lets you choose from either the popular search engines or a very comprehensive list of specialized search engine/databases in a number of fields. Yahoo, search.com, and EasySearcher all provide help with entering your search phrase. Most Web portal sites offer a quickly-located search entry box that connects you to the major search engines.
How to Search
For "tips" on entering your search argument, see each search engine, including Yahoo's . It's good to read the information at least once. By "How to Search," we mean a general approach to searching: what to try first, how many search engines to try, whether to search USENET newsgroups, when...