Google & Valid html experiment

Just followed this interesting seo experiment that proves - or at least gives a strong clue - that Google cares about valid xhtml.

The experiment looks easy to understand. They created a web site that has 4 duplicate pages but they had :

• 1 Valid Html + CSS
• 1 Valid HTML + Invalid CSS
• 1 Invalid HTML + Valid CSS
• 1 Invalid HTML + Invalid CSS

They used the same anchor text to link to these pages, and for some reason Google picked the page that has valid xhtml & CSS. This may not mean something by itself, but I guess the fact that Google recognizes valid pages give me something to think for the future :)

I noticed that websites after an update (to valid code) getting a better ranking in the SERP's

Interesting, one more reason to make sure your markup is valid.

I knew it... always been a validation evangelist...