Only 1 in 6 users of internet search engines can tell the difference between unbiased search results and paid advertisements, a new survey finds. Though it polled only adults, the survey's results underscore the need for educators to teach their students how to understand and evaluate carefully the information they find online--particularly as today's generation of students increasingly turn to the web as their primary research tool.

The Pew Internet and American Life Project reported on Jan. 23 that internet users in the United States are generally naive when it comes to how search engines work.

The major search engines all return a mix of regular results, based solely on relevance to the search terms entered, and sponsored links, for which a web site has paid money to get displayed more prominently.

Google Inc. marks such ads as "sponsored links," Yahoo Inc. terms them "sponsor results," and Microsoft Corp.'s MSN uses "sponsored sites." Such ads are placed to the right and on top of the regular search results, in some cases highlighted in a different color.

But only 38 percent of web searchers even know of the distinction, according to the Pew survey, and of those, not even half--47 percent--say they can always tell which are paid. That comes out to only 18 percent of all web searchers knowing when a link is paid.

Forty-five percent of web searchers say they would stop using search engines if they thought they weren't being clear about such payments, yet 92 percent of web searchers say they are confident about their searching abilities.

Deborah Fallows, a senior research fellow at Pew and the study's author, said the findings were surprising given that the same people are likely to know the difference between television programs and infomercials.

"We're still in the infancy of the internet," Fallows said. "People are still kind of so pleased that they can go there, ask for something, and get an answer that it's kind of not on their radar screen to look in a very scrutinizing way to see what's in the background there."

She said the results reflect blind trust on the part of the web searcher rather than "anything nefarious on the part of the search engine."

Nonetheless, the Consumer Reports WebWatch studied the top 15 search engines and found many of them could do better in disclosing sponsorships, particularly when they practice "paid inclusion." That is when sites pay to make sure they are included in a search engine's index, though without guarantees that their links will be displayed more prominently.

The telephone-based Pew study was conducted May 14 through June 17 and involved 2,200 adults, including 1,399 internet users. Results based on internet users have a margin of sampling error of plus or minus 3 percentage points.

The survey results are a reminder that search engines have become an accepted first step in finding information for all age groups, without enough attention paid to deciphering the particular "forms and features" of each search engine, said Nancy Messmer, director of library media technology for the Bellingham, Wash., school system.