Search Engines Sort out the Tangled Web

Article excerpt

First of two parts

Reader KMP sent an e-mail requesting that I explain the mighty search engine. For the next two weeks I have decided to suspend the normal format of Web Wise and take an extended look at how to find stuff on the World Wide Web.

The Web offers more than 50 million pages of raw data created by corporations, nonprofit organizations, schools, individuals and special-interest groups. To sift through this vast sea of information, the user needs a search engine, or a mechanism, to acquire the Uniform Resource Locator (URL) address.

To understand the function of the search engine, the user may wish to view the WWW as a library building filled with shelves of books, which are the millions of sites. Within any library, only a small portion of the information may be relevant to a particular user. Within the virtual library, the search engine acts almost as a card catalog file that helps the users find the site or information they need.

The most common search engines are Alta Vista, Excite, Magellan, Infoseek and Yahoo. Each search engine can be viewed as a Web site accessed through a fairly common URL syntax that contains their name (http://www.(search engine name).com). Each of these search engines provides different features and services from yellow pages to local area site searches, and each will produce a different response to an identical search request.

For the purpose of this article, Web Wise is going to be comparing Yahoo, a category or hierarchical search engine, and Alta Vista, sort of the big brother of Yahoo. Alta Vista provides a wider sweep of the Internet.

Yahoo provides search results based on 14 categories of information from arts and humanities to business opportunities - national and regional.

A category search engine provides access to a limited number of pages, though the overall depth of the database is in the millions of sites. Using the library analogy, Yahoo reads the book and displays the title. Alta Vista reads the same book and displays its pages.

Sites have been previewed by Yahoo staff and placed into the variant categories. Therefore, to best use Yahoo, you need to be able to discern the category of information to which a query, or question, best responds.

Category search engines provide a popular service as they basically walk the user through the search process and return a targeted, and usually defined, number of sites in the research results. Conversely, using a search engine that will reference the entire depth of the Web, such as Alta Vista, will often return search results containing thousands of sites.

Search engines such as Alta Vista reach out through what are called "spiders." These information retrievers actually scurry out to all of the pages of sites, search for key words or concept queries, and return all the sites that it can find. The Alta Vista computer is kept up to date by continually searching all the sites on the Web so that when requested, a site's location and contents are accessible.

Comparing Yahoo to Alta Vista, the search request for information on how to build a wooden bookcase is an excellent example of the strengths of these two very different engines.

A simple Web search is conducted using a key word or concept/phrase. …