On August 8th, 2005 Tim Mayer of Yahoo! posted on the Yahoo! Search Blog that the "[Yahoo!] index now provides access to over 20 billion items" which include "19.2 billion web documents, 1.6 billion images, and over 50 million audio and video files".  Two days later, on his blog, University of California at Berkeley Visiting Professor John Battelle reported that Google refuted this claim saying "[their] scientists are not seeing the increase claimed in the Yahoo! index".  In order to test Yahoo!’s claims, Matthew Cheney and Mike Perry, two researchers working for the National Center for Supercomputing Application (NCSA) under the supervision of Associate Director Dr. Orville Vernon Burton, conducted a brief study of the indices of the two search engines.
I’ve been using Google since it first became available. I make it the startpage on every computer I use on a regular basis. I make it the start page on every computer of every user at work. I install the Google toolbar on all these computers as well.
In fact, in the 10,012 test cases we ran, only in 3% of the cases (307) did Yahoo! return more results. In 96.6% of the cases (9,676) Google returned more results. In less than 1% of the cases (29) both search engines returned the same number of results.
[This item originally posted on livejournal.com]