Panda History
Google is constantly making changes to the algorithm which determines where a website will be ranked in the SERPS (Search Engine Results Pages). Starting on February 23, 2011, a very large change that affected 11.8% of search queries was released by Google. They eventually named this algorithm change, the Panda Update1.
The goal of the Panda Update was to increase the search engine rankings for high quality sites and decrease them for low quality sites.
So, what makes a site a “high quality site?” The Google Webmaster Central Blog2 lists a large number of things that they look for when assessing quality. Here is a summary of that list:
Are the articles on your site full of good detailed information, or very shallow?
Do you have duplicate content? This could mean that content is duplicated on multiple pages or that you have content that is duplicated on other sites across the web.
Do you have spelling errors?
Do your articles provide original content that can’t be found elsewhere on the web?
Would people want to bookmark and share your content?
Are there a distracting number of ads on your pages?
If your site was directly affected by Panda, then the drop has to be immediately after one of these dates. These are the dates of the Panda updates3:
Here are the dates of the known Panda updates
Februrary 23, 2011
April 11, 2011
May 9, 2011
June 21, 2011
July 23, 2011
August 12, 2011
September 28, 2011
November 18, 2011
January 18, 2012
February 27, 2012
March 23, 2012
April 19, 2012
April 27, 2012
June 8, 2012
June 25, 2012
July 24, 2012
August 20, 2012
Sep 18, 2012
Sep 27, 2012
Nov 5, 2012
Nov 21, 2012
Dec 21, 2012
Jan 22, 2013