Google Panda is change to the Google’s search results ranking
algorithm ,It was first released in Feb 2011. The change aimed to
lower the rank of “low-quality 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 or 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 published an advisory on its
blog[citation needed], thus giving some direction for self-evaluation of
a website’s quality.
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, made possible by and named after engineer
Navneet Panda, 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
‘Penguin’ update was released, which affected a further 3.1% of all
English language search queries, highlighting the ongoing volatility of
search rankings.
source: http://en.wikipedia.org/wiki/Google_Panda
