The World Wide Web provides a universe of educational resources, but instructors may feel "lost in space" when they begin searching through it for relevant materials. Here are a few guideposts to help you find Web resources that you and your students can use, without spending a lifetime online.

Search Tools. The Web consists of millions of different sites, with many up-to-date, informative sites available on most any topic. Unfortunately, there is also plenty of outdated, incorrect, or otherwise useless "information" on the Web. Fortunately, tools exist to help you find the materials you need.

Web directories and portal sites.

Web directories. Web directories are services that catalog Web sites by category. They are like "tables of contents" for the Web. Beginning on a directory's home page, users select from a number of broad categories (such as "Entertainment" or "Science") and then choose from progressively narrower subcategories ("Movies" and then "Reviews," for example, or "Astronomy" and then "Eclipses"), until they reach a targeted list of relevant Web sites. Most Web directories, such as Yahoo! and About.com, have real people review sites submitted for inclusion, to ensure that the sites they list are of sufficient quality and are placed in the appropriate categories.

Portal sites are specialized directories covering a single interest or a narrow range of topics. Some are quite large, providing links to hundreds of other sites. Portal sites are themselves often listed "high up" in Web directories and are a good place to begin a search of the Web.

Web search engines. Search engines are like "indexes" of the Web. Users enter a "search string," or group of keywords, on the site, and the engine returns links to Web sites that contain the same keywords within their own pages. Users can control how results are returned by using Boolean operators (AND, OR, NOT) or symbols (+, -, " ") in search strings to include, exclude, and group keywords. The most useful search engines include an advanced or "power" search feature that lets users further refine how results are returned. Power searches can filter out sites that haven't been recently updated, purely commercial sites, personal home pages, and so on, or restrict results to sites published by specific types of organizations, such as universities or government agencies. Used skillfully, search engines are a great way to find targeted, specific information on the Web. Major search engines favored by academics include Google, Lycos, AltaVista, and NorthernLight.

Webrings. Webrings are groups of related Web sites that agree to link to one another to increase their exposure on the Web. Member sites include a box at the bottom of their home page with links to the "next" or "previous" site in the ring or to a randomly selected member site. Webrings are a way to navigate the Web in a manner more directed than random surfing but less restricted than relying solely on directory or search engine results. Surfing around a webring, you may encounter sites that do not place high on search engine results but still contain useful information. There are webrings on hundreds of topics, from the rain forest to baseball to folk music. Yahoo! provides a free webring service, with a directory of its webrings posted at http://dir.webring.yahoo.com/rw. Many more webrings can be accessed through RingSurf at http://www.ringsurf.com.

Mailing lists, newsgroups, and IRC.
Although these technologies are separate from the World Wide Web, they are now accessible from Web pages.

Mailing lists. An electronic mailing list is a service that allows individuals to send messages about a specific topic to a large group of people interested in that topic, simply by e-mailing the list server. At a specified period, usually once daily, all messages sent to the list server are compiled and e-mailed out to the list subscribers. There are mailing lists on thousands of academic subjects; mailing list posts can be a good source of cutting-edge information and current academic debate. Many lists now maintain archives on Web sites, and some allow people to post messages from a Web page instead of by e-mail. List directories include the Mail Archive at http://www.mail-archive.com/ and E-Scribe at http://www.escribe.com.

Newsgroups are similar to mailing lists, except messages are not compiled and e-mailed to subscribers but are stored on a news server as they are received. Subscribers can log on at any time to retrieve messages posted since their last visit. The Google Groups Web site at http://groups.google.com offers an exhaustive directory of newsgroups and a twenty-year archive of newsgroup posts.

Internet Relay Chat (IRC) allows users to "chat" in real time via typed messages. There are thousands of chat groups on the Internet, devoted to myriad topics. Like mailing lists and newsgroups, many chat groups now provide archives accessible from the Web. University Web sites are a good place to look for chat archives useful to educators.

Evaluating what you find. Finding sites is only the first step in a search of the Web; evaluating what you find is a second, crucial task. Anyone with a computer and a modem can publish a Web site or post to a mailing list or newsgroup, and there is no central authority monitoring the accuracy and timeliness of the Web's contents. Here are a few tips to pass on to your students about evaluating information they find on the Web:

• Consider the source. Who published the site or posted the message? Look for the author's or message poster's credentials.
  The first clue to the source of a Web site is in the domain name. Sites with a URL ending in .edu belong to a college or university. Those with a .gov URL are published by government agencies. These are generally reliable sources of information. (Remember, however, that .edu sites may be published by students, not by the institution.) Most other domain name extensions, including .com, .net, .org, and .info, can be owned by anyone--Internet registration authorities no longer differentiate between them.
  
  
• Evaluate the site's goals and objectivity. What is the site's purpose? Is it purely informational, or is the site trying to sell something? Is the site objective or is it promoting an agenda?
  
  
• Evaluate the writing and design. Is the site or post well written? Is the site carefully designed, with links that work? These are clues to the reliability of the information.
  
  
• Check the date. Is the site or message current, or was the information posted years ago? Many sites indicate when they were last updated, and even if the site itself does not provide this information, some search engines do in their results lists.