Sémantique HTML et PageRank

Mike Davidson tried to rank for the term lodefizzle on Google. He wrote a dozen different pages to find out what aspects of HTML Google really cares about. Scroll down to the Google…

• The H1 tag does indeed assert some dominance and we can therefore assume you are better off using proper headings in your HTML documents.
• The mere appearance of many nested tables in your code does not have a strong enough negative effect to be considered a drag on search engine ranking.
• It's not clear that validity helps search engine ranking, but it's definitely true that certain errors in your code can get you completely removed from indexes.
• The semantic effect of hierarchical HTML headings is a stronger factor in search rankings than more rudimentary measures such as physical keyword placement.
• Although good semantics are somewhat valuable in optimization, simple things like proper titles, descriptive filenames, and incoming links are dramatically more important.