Google accuses Microsoft on search data; Market leader says rival copies query results

Matt Cutts, head of search quality at Google, called the Microsoft practice “crazy”, and challenged the company to reveal how much data it had collected from Google users and how this was being used to determine results on its own Bing search service.

The software group did not deny the claims directly, but said that Google’s allegations were based on “a few outlier examples”. It also claimed that using data about what internet users did on Google to help refine its Bing service reflected general practice on the web, where internet services learn from wider online behaviour.

The dispute broke out after Google released the results of a test it carried out to try to show that Bing was copying its results.

It posted dummy results on the Google search engine in response to deliberately garbled queries. When carried out later on Bing, the queries returned the same dummy responses, Mr Cutts said.

Microsoft had captured the data about searches on Google through its Internet Explorer 8 browser and toolbar, which send details of “clicks” back to Microsoft when users accept certain settings on the Microsoft software, he added