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To access the contents, click the chapter and section titles.
Platinum Edition Using HTML 4, XML, and Java 1.2
keywords and description, however, are not officially defined components of HTTP headers, although they can be implemented as part of the META NAME tag, such as the following: <META NAME=”keywords” CONTENT=”keyword1 keyword2 keyword3"> <META NAME=”description” CONTENT=”This site contains...”> Despite this, you will see many pages that utilize the improper <META HTTP-EQUIV=”Keywords” NAME=”Keywords” CONTENT=”blah, blah”> construction. This may seem to be a quibble, yet what’s important is getting search engines to recognize your keywords and descriptions. Some search engines, including AltaVista, InfoSeek, and HotBot, pay particular attention to META description and META keywords entries. These services index terms in both the Description and keywords tags and use the META description rather than the first few lines of the page to identify the URL in returned searches. All three of these engines look for the proper syntax, and it is not known what they will do with META HTTP-EQUIV tags. Other search engines, such as Excite, may explicitly ignore these fields due to the potential for abuse. See http://www.clackamas.cc.or.us/instruct/cs/classes/178/search/s-meta.htm for more information. In fact, at least one lawsuit has been filed regarding keyword abuse. Use of these META tags is becoming more popular. According to an analysis by Dave Beckett of the University of Kent at Canterbury The following is an example of using the META keywords tag within an HTML header:
<HEAD>
<META name=”description” content=”ACNielsen Consumer Information”>
<META name=”keywords” content=”consumer panel,
consumption,
marketing research”>
<title>Buying Habits of Internet Users</title>
</HEAD>
After the search engine indexes this page, if a user searches for “marketing research,” the engine will find this page even if the words “marketing research” do not appear anywhere in the text of the page. Using Keywords in HTML Comments This section presents some lines from an HTML file that lists links to English language newspapers. The lines aren’t keyed; to find a match, therefore, you must enter a query that exactly matches something in either a particular line’s URL or its visible text. Such matches are not too likely with some of these example lines. Only one of them comes up in a search for “Sri Lanka.” None of them comes up in a search for “South Asia.” <B><A HREF=”<http://www.lanka.net/lakehouse/anclweb/dailynew ⇒ /select.html”>Sri Lanka Daily News</A></B><BR>> <B><A HREF=”<http://www.is.lk/is/times/index.html”>Sunday Times ⇒ </A></B><BR>> <B><A HREF=”<http://www.is.lk/is/island/index.html”>Sunday Island< ⇒ /a></B><BR>> To improve the search results, you can key each line with one or more likely keywords. The keywords can be contained within <!--comments -->, in <A NAME=...> statements or in ordinary visible text. Some of these approaches are more successful than others. The following are examples of each. First, add some keywords as HTML comments on each line. The following example already looks better: <!--South Asia Sri Lanka --> <B><A HREF=”>>http://www.lanka.net/lakehouse/anclweb/dailynews ⇒ /select.html”>Sri Lanka Daily News</A></B><BR>< <!--South Asia Sri Lanka --> <B><> HREF=”>>http://www.is.lk/is/times/index.html”>Sunday Times ⇒ </A></B><BR>< <!--South Asia Sri Lanka --> <B><< HREF=”>>http://www.is.lk/is/island/index.html”>Sunday Island< ⇒ /a></B><BR>> You could put the keywords in <A NAME=...> statements also, but HTML prohibits spaces in <A NAME=...> statements. Therefore, keys in an <A NAME=...> statement are limited to single keywords rather than phrases. This might suffice if you can always be sure of using an AND or OR search instead of searching for exact phrases. But many scripts don’t support Boolean operators, and even when Booleans are allowed, most users don’t use them. So, overall, using <A NAME=...> statements for keying isn’t the best choice. Nevertheless, the following is an example of using an <A NAME=...> statement to provide a keyword: <A NAME=”Tamil”> Leveraging Commercial IndexesFortunately, you don’t have to be a natural language or artificial-intelligence expert to incorporate indexing into your home page or Web site. If you want to offer your users the capability to search the Web for items of interest, you can include links on your site to the commercial search engines. You may also want to help your users define their searches by topic by passing parameters to these commercial search engines. Many fine public search engines are available. This section examines some of the more common commercial indexes and how you can use them to provide services for your site. Public indexes are available for free through sponsoring corporations, groups, or individuals and are usually accessed through an HTML form and a CGI program. You don’t have to rely on a list of bookmarks or your browser’s setting to use a search page. You can put a page on your site that links directly to your favorite search engines. You can even tailor the form so that it comes preloaded with specific search terms, or, with a little more effort, make a massive commercial index return only pages from your own site when queried. Using AltaVista to Search Your SiteAltaVista provides a helpful index of Web sites and newsgroups (see Figure 31.1). You can find AltaVista at the following address: http://www.altavista.digital.com/
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