Internet search leader Google is experimenting with a new tool for its online search engine that lets users vote on search results in a manner similar to social news sites.

Google Labs unveiled the new tool in a limited release with an aim "at improving the search experience," the company said in a statement on Thursday.

The program lets users influence search results by adding, moving and removing items. When searches are conducted again with the same keywords, the changes are retained, the company said.

The experiment appears to borrow some of the qualities of social news sites like Digg and Reddit, which rank news based on reader-generated voting. But it differs in that the results appear to be personalized to the specific user, and don't have an impact on how other people's searches are performed.

The experiment may also be short-lived: the company cautions that "this is an experimental feature and may be available for only a few weeks."

Google's traditional search method relies on a page-ranking system. Pages are ranked higher the more times other pages link to it. Links from popular pages also receive more weight in the ranking system.

Social media advocates have been critical of Google's search for relying too much on automated results that can be tricked into prioritizing some websites over others.

Last year Wikipedia founder Jimmy Wales told the Times of London the search engine was "broken," that while it was good at some types of searches, other times "it produces nothing but spam and useless crap."

Google, however, remains the leader among search engines, ahead of  second-place Yahoo Inc. In October, Google reported revenues of $4.23 billion US for the quarter ending Sept. 30, 2007. The bulk of these revenues are generated through advertising on Google's network of web sites.