
The overlap in first-page results is less than one per cent across the four major search engines - Google, Yahoo, MSN and Ask - because they use different algorithms to rank pages.
The study was commissioned by metadata firm WebFetch and carried out by researchers at the Queensland University of Technology and Pennsylvania State University.
The findings also suggest that the difference between the results the search engines throw up has increased over the past two years.
Only 0.6 percent of 776,435 first-page search results were the same across the top four search engines.
The research expanded on a similar overlap study conducted in 2005 and found that the major engines produce even fewer of the same results today than they did just two years ago, simply because the web is constantly expanding.
"People who depend on just one engine are choosing to limit their search potential," said Dominic Trigg, vice president of search and directories at InfoSpace, the company behind WebFetch.
"There may be hundreds of relevant hits omitted from a results list, simply because of a particular search algorithm that your chosen search engine uses."
WebFetch is a metadata company, and Trigg claims that the only way to ensure rounded search results is to use a meta search engine which aggregates searches from other search engines and specialist sites like Blinkx and Kelkoo.