Google Panda Update

Google Panda Algorithm UpdateThe Google Panda Update is a significant change to Google's search ranking algorithm that was first released in February 2011. The change focuses on lowering the rank of low-quality websites (or thin sites), and return the higher-quality sites nearer to the top of the search result pages.

Some providers reported a surge in the rankings for news related websites and social networking sites, and a drop in rankings for sites containing large amounts of advertising.

This update was reported to have affected the rankings of almost 12 percent of all search results, one of the widest reaching updates to date.

Soon after the Panda update rollout, Google's webmaster forum became filled with complaints of scrapers/copyright infringement getting better rankings than the sites containing the original content, and at one point, Google publicly asked for data points and information to help detect scrapers.

Panda has received several updates since the original roll-out, and the effect went global in April 2011. To help affected website owners and publishers, Google provided an advisory on its blog, giving some clear direction for self-evaluation of a website's quality. They have provided a list of points on its blog answering the question "What is a high-quality site?", designed to help webmasters peek into Google's mindset.

This was a significant algorithm update that used artificial intelligence in a more sophisticated and scale-able way. Human quality testers rated thousands of sites based on various aspects of quality, including site design, trustworthiness, website speed, and whether or not they would return to the website. Google's new machine-learning algorithm was then used to look for similarities between websites people found to be high quality and low quality.

Many new ranking signals have been introduced to the Google algorithm as a result, while older, less intelligent ranking factors such as PageRank have been downgraded in weight as a ranking signal.

Panda is updated from time to time and the algorithm is run on the Google network on a regular basis. In April 2012 the Google Penguin update was rolled-out, affecting a further 3.1% of all English search queries.

In September 2012, a Panda update was confirmed by Google via its official Twitter page, where it announced; “Panda refresh is rolling out - expect some flux over the next few days. Fewer than 0.7% of queries noticeably affected".  Another Panda update was released in January 2013, affecting about 1.2% of English queries.

Panda vs Previous AlgorithmsGoogle Panda affects the ranking of an entire website, or even a specific section of a site, as opposed to targeting specific individual pages.
In March 2012, Google updated Panda and stated that they were deploying an "over-optimization penalty," in order to level the playing field.
Panda RecoveryGoogle says that it only takes a few pages on a site containing poor quality or duplicative content to hold down your rankings (and traffic) on an otherwise good quality site, and recommends such low quality pages be removed from the site, blocked from being indexed by the search engine, or rewritten, and must be of a sufficiently high quality, as such content brings "additional value" to the web.
Website content that is broad or general, non-specific, and not substantially different from what is already available on the web should not be expected to rank well: Those sites are not bringing any additional value.
The key to recovery from the Panda update seems obvious; fill our websites with fresh, unique and high quality content that has not been begged, borrowed or stolen from elsewhere. Bring something new by adding value in some way with unique insights, reviews, related facts and resources.
Prevent all pages that do not offer such high quality content from being indexed by search engines using meta tags in your pages, or a robots.txt file.