From the Wall Street Journal
By AMIR EFRATI
Google Inc., long considered the gold standard of Internet search, is changing the secret formula it uses to rank Web pages as it struggles to combat websites that have been able to game its system.
The Internet giant, which handles nearly two-thirds of the world's Web searches, has been under fire recently over the quality of its results. Google said it changed its mathematical formula late Thursday in order to better weed out "low-quality" sites that offer users little value. Some such sites offer just enough content to appear in search results and lure users to pages loaded with advertisements.