SEO Tutorial
Introduction
As we stated in the Accessibility tutorial, a website is coded in some flavor of HTML or XHTML. A validation tool can assess such a document and determine whether it passes or fails against the document type that is declared. Similarly, a CSS (cascading style sheet) document also can be validated against a certain standard and will either pass or fail. In both cases the results are definitive. We further stated that while there are tools to test a website's accessibility, and while sites can clearly fail at well-defined points, lack of failure does not constitute an accessible site. The knowledge that a site has passed only means that the developers have given the site a certain level of accessibility. The only way to fully test for accessibility is to examine the code and peruse the site using a number of screen readers and other tools.
It is similarly difficult to ensure that a site is SEO-optimized, because there are no definitive and comprehensive analytical tools, there are several major players (Google, Yahoo, Bing, etc.), and algorithms are not published. SEO-optimization is an ongoing process of trial and error. Moreover, it is a moving target because the algorithms will change, especially as people try to trick search engines.
One need only search for "SEO myths" to see the number of challenges to conventional wisdom. This article too challenges some of the oft-repeated assertions. Such is the state of our knowledge, and such is misinformation in the "age of information". I gladly invite the reader to test the validity of all my assertions.
Black Hat and White Hat SEO
Black Hat SEO can be simply summed up as unethical attempts to trick search engines. Search engines are very sophisticated and can ferret out these usually vain attempts at promoting a site's ranking. These methods include creating link farms, or sites whose sole function is to link to pages and thus increase the strength and number of inbound links. Another method is to insert an abundance of keywords into the pages rather than using natural language, known as keyword stuffing. These are hidden using CSS properties like display set to "none" or visibility set to "hidden", using the same color text as the background color, or absolutely positioning the keyword off the screen. This last method is legitimately used to hide text from visual browsers and yet expose them to screen readers. Search engines are programmed to tell the difference. There are other black hat methods, but using them is not only unethical, but will likely penalize you.
White Hat SEO is simply an ethical approach that follows certain basic rules and natural language. To put it simply, a site rises in rankings in proportion to the natural richness of its content, with the caveat that that content needs to be structured and wrapped in intelligent ways.