Feb 3, 2011 12:16 GMT  ·  By

Microsoft claims Google resorted to click fraud in order to manipulate Bing's search results so that it could later publicly accuse it of cheating.

Microsoft and Google are at each other's throat since earlier this week when the Mountain View search giant announced that Bing is replicating its results.

To gather evidence of the alleged cheating, Google hardcoded results for some very improbable search queries and waited to see if they are copied by Microsoft's search engine.

The company's search engineers choose some 100 randomly generated terms that are unlikely to mean anything in any language, such as "hiybbprqag" or "mbzrxpgjys," and which returned no search results in either engines.

They then forced Google Search to display some unrelated pages as results for each of them and used the search queries on Google at home from Internet Explorer with the Bing toolbar installed.

The result of the honeypot experiment was that in about half-a-month the exact same results began appearing in Bing for some of the terms.

They determined that this was likely the result of clickstream data gathered by the Bing toolbar being used to refine search results.

For example, if an Internet Explorer user searches for a term on Google and then clicks on a particular result, the Bing toolbar collects that data and sends it back at Microsoft.

If the data shows enough users clicking on the same result for the same search query, then Bing's search algorithms automatically consider it more significant and pushed it at the top.

Since this user decision data is collected from other search engines, Google believes it is cheating. The company says that even though it also gathers clickstream data through Chrome, it never used it to improve search results.

Microsoft on the other hand says that clickstream data collected by the Bing toolbar is just one of the 1,000 signals used to refine search accuracy and describes Google's experiment as a cloak and dagger click fraud attack.

"That’s right, the same type of attack employed by spammers on the web to trick consumers and produce bogus search results," says Yusuf Mehdi, senior vice president of Microsoft's online services division.