Google has been running a live test in which web users have been re-ranking, commenting on, and even removing search results, but the company is unsure whether these features will ever be introduced for widespread use.

The search engine has been running a few variations on these tests; and has used the feedback to learn more about the quality of their results.

According to Google’s Matt Cutts:
“It’s a really fun experiment; I can’t say for sure whether it will go live for everybody because we’re always running a ton of experiments. Only some of those — the ones that are being very successful — are launched live for everybody.”

Some have criticized Google for being too closed to user participation, and there are other search engines which have opened u to user participation –  Mahalo and Wikia Search both rely on contributions from the public to rate and improve their search results pages.

However, there are plenty of people who would have a lot to gain by manipulating Google’s result pages, to promote their own sites, or move those of competitors’ further down the page, and this would make any such system very difficult to police.

Cutts also argues that Google’s results already use some user input:
“A lot of times people think about Google as being nothing but algorithms and computers operating around the clock,” he said, “But if you think about [Google’s proprietary ranking system] PageRank, the way we judge how reputable a particular page is boils down to human judgments and actions in the sense that it depends on who is linking to whom on the Web.”