The survery investigated over 460 Web sites worldwide and warned consumers "must use extreme caution" when getting information using the Internet.
Health and finance sites are singled out for particular criticism - 49 per cent of those surveyed didn't advise just how information should be used.
In particular, they didn't warn people that they should consult professionals.
Around the same percentage of sites in these sectors didn't back up the credentials of their advice.
Thirty per cent did not give an address or telephone number.
For price comparison sites, only 41 per cent gave sources for their prices, while a staggering 60 per cent did not say whether their content was influenced "by commercial interests".
The general conclusion is that people are attracted to a Web site more by its appearance than its content, and should check the background of a site before making business decisions.
The Consumers International web site. My! Isn't it pretty! µ