JAB_Creations - 6:49 pm on Jul 8, 2010 (gmt 0)

Google likes HTML5 because the elements are more descriptive. In a previous post it was revealed that Google wanted class attributes on every element to understand the context of the content (e.g. class="menu" class="sidebar").

At the same time Google likes more content and less code.

Google has also done lots of research to understand what elements, attributes, and values are most common.

The best way to balance this is to make a good balance between using unique id's, classes, and understanding how CSS 1.0 works...yes, way too many people don't even understand how basic CSS works.

In general I give id's to a lot of elements to make working with JavaScript much easier though it also makes it much more descriptive for robots indexing each page.

The key I think when determining the names of unique id's and classes is to choose very common values such as "side" or "aside" (if HTML5 is still using that as an example).

Also having valid XML markup that won't break if it were to be served as application/xhtml+xml should be a high level goal. There is no doubt in my mind that Google engineers have spent time figuring out where the end tag for the following element would be on a page on a site such as mine...

<div id="content">

Since Google loves low code to content ratio using divisible elements with CSS1 effectively is important. Often you have to use two divisible elements to achieve certain styling goals however by knowing how to use selectors effectively (e.g. #side div {margin: 8px;}) you won't need to add excessive classes or id's.

In the end once your site recovers I think that you'll find it overwhelmingly worth your effort and time. I'm currently working on the 29th version of my site and I've changed the HTML and then XHTML code so much over the years but the site has a reasonable PR even without strong external references.

My biggest advice is since your site does not make changes like this frequently (e.g. been the same for 13 years) to not freak out, put it back, and make the site look like it's trying to gauge Google's rankings because then it'll make your site look spammy or not trustworthy. Anyone worth giving good PR to on Google is going to update their code to keep their site from reeking of the 90's. I'm sure just as other web designers dispise working with IE6 that Google engineers probably don't desire to work with older and often broken HTML code when trying to determine a site's PR.

- John