Consumers who visit multiple search engines looking for the best prices or products may be wasting their time because results vary little between sites, US researchers claimed today.

Dr Jim Jansen, assistant professor in the College of Information Sciences and Technology at Penn State University, reported in a recent study that there is "no significant difference in the effectiveness" of five popular search engines in helping consumers find what they are looking for.

"What we learned is that there is little benefit for consumers who occasionally shop online to visit various search engines for product comparisons as those engines basically return nearly identical results in terms of effectiveness," said Dr Jansen.

The study also indicated that sponsored links paid for by businesses are no more relevant to consumers than organic or non-sponsored links which are returned automatically by a search engine's algorithms.

But Dr Jansen said that some advantage to using niche search engines designed for e-commerce can be gained for those consumers who primarily do their shopping online.

"Basically, e-commerce search engines will give consumers one more relevant result in a group of 40 links," he said.

"This is not a significant increase for consumers conducting a single search, but for people doing numerous searches every day, the performance increase could be considerable."

Independent evaluators analysed each link for relevance, comparing the original query with the returned results. From their analysis, Dr Jansen and co-author Paulo Molina determined that the five main search engines returned nearly identical results in terms of relevance.

The individual engines selected were Excite (meta search), Froogle (e-commerce search), Google (general purpose), Yahoo Marketing Services (pay-per-click) and Yahoo Directory (categorised websites).

Niche search engines, such as those designed for e-commerce, are assumed to perform better in returning relevant results than all-purpose search engines. But this is not the case, according to Dr Jansen.

"E-commerce search engines or directory services do return slightly more relevant results per query, but for most consumers the difference is minimal," he explained.

The study will be published in July's Information Processing & Management.