is a change to Google‘s search results ranking algorithm that was first released in February 2011. The change aimed to lower the rank of “low-quality sites” or “thin sites”, and return higher-quality sites near the top of the search results. CNET reported a surge in the rankings of news websites and social networking sites, and a drop in rankings for sites containing large amounts of advertising. This change reportedly affected the rankings of almost 12 percent of all search results. Soon after the Panda rollout, many websites, including Google’s webmaster forum, became filled with complaints of scrapers/copyright infringers getting better rankings than sites with original content. At one point, Google publicly asked for data points to help detect scrapers better. Google’s Panda has received several updates since the original rollout in February 2011, and the effect went global in April 2011. To help affected publishers, Google provided an advisory on its blog, thus giving some direction for self-evaluation of a website’s quality. Google has provided a list of 23 bullet points on its blog answering the question of “What counts as a high-quality site?” that is supposed to help webmasters “step into Google’s mindset”.
Google Panda was built through an algorithm update that used artificial intelligence in a more sophisticated and scalable way than previously possible. Human quality testers rated thousands of websites based on measures of quality, including design, trustworthiness, speed and whether or not they would return to the website. Google’s new Panda machine-learning algorithm was then used to look for similarities between websites people found to be high quality and low quality.
Many new ranking factors have been introduced to the Google algorithm as a result, while older ranking factors like PageRank have been downgraded in importance. Google Panda is updated from time to time and the algorithm is run by Google on a regular basis. On April 24, 2012 the Google Penguin update was released, which affected a further 3.1% of all English language search queries, highlighting the ongoing volatility of search rankings.
On September 18, 2012, a Panda update was confirmed by the company in 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 began rolling out on January 22, 2013, affecting about 1.2% of English queries.
Google says it only takes a few pages of poor quality or duplicative content to hold down traffic on an otherwise solid site, and recommends such pages be removed, blocked from being indexed by the search engine, or rewritten.However, Matt Cutts, head of webspam at Google, warns that rewriting duplicate content so that it is original may not be enough to recover from Panda — the rewrites must be of sufficiently high quality, as such content brings “additional value” to the web. Content that is general, non-specific, and not substantially different from what is already out there should not be expected to rank well: “Those other sites are not bringing additional value. While they’re not duplicates they bring nothing new to the table.”.