META tags and Search Engines
Overview The <META> tag lets you control, to some degree, the information gathered and indexed by web-based search engines. Most search engines use various algorithms to attempt to extract the key concepts and topics of a website from the <TITLE> as well as the first few paragraphs of text on a page. However, a number of the leading search engines -- Alta Vista, Infoseek and others -- will use <META> tag information if present within the <HEAD> of an HTML page.The KEYWORDS and DESCRIPTION Tags <META> tags have this general form:
<META http-equiv="something" name="something" content="content">
In practise, the "http-equiv" and "name" are identical, and usually the "http-equiv" is omitted.
The description tag looks like:
<META name="description" content="A 200 maximum character description of your site">
The keywords tag looks like:
<META name="keywords" content="list, comma separated, keywords, phrases,1000 characters max ">
How it Works Normally, search engines use the TITLE and the first 200 characters of text they find on a page as the description. This is often less than helpful as a site description. Here's an example of site found by an Infoseek search on "Biology education":
Biology Education for the Information Age
AGENDA FOR CURRICULUM REVISION Back to the Home Page Expectations and
Opportunities: Current career paths for graduating biology majors include
further matriculation in graduate ...
54% http://brl.med.umn.edu/brl_4.htm (Size 11.0K)
By using the META description tag to control the description presented to search engine users, you retain much more control over the information a potential site visitor first sees about your site.
Search engines also extract keywords from the TITLE and first paragraph (or more -- some engines, Lycos among them, search down the page until they feel they have enough text to summarize or from which to extract relevant keywords). By using the META keywords tag, you can control your site's relative ranking in searches. There is a caveat though: increasingly, search engines penalize for or discard entirely keywords that appear too often. The current (arbitrary) threshold seems to be about seven unconnected appearances of a keyword.
Most search engines use all of the above techniques. For example, Infoseek and Alta Vista extract keywords from TITLE, text and META tags if all are present on a page. That suggests that for maximum variation and exposure, you might want to use different wordings in the TITLE, description tag and first paragraph, combined with limited and judicious re-use of especially relevant keywords.
More Information Here are two links that we have found useful in understanding search engines and META tags:
META Tag Information Page