Lack of clear-cut, understandable privacy policies could be the biggest impediment to online retailers this year as they gear up for the hectic fourth-quarter, holiday-buying season.

A new study released last week by Forrester Research and Vividence, a US-based company which specialises in evaluating Web sites, found that the more satisfied online buyers are with a Web site's privacy policy, the more comfortable they will be when they shop at that site.

The Forrester study, Web buyers speak out about privacy policies, surveyed 400 Web buyers and analysed their attitudes toward online privacy on eight major retail sites including Amazon.com, JCPenney.com and Walmart.com.

The Web buyers rated each site's privacy policies from zero to 100, based on the ease of locating the policy, their overall satisfaction with the policy and their comfort level in shopping at the site after reading the policy. At least five of the sites received "mediocre" scores of between 60 and 76 because of policies that were difficult to understand or failed to explain terms and principles. The site that received the lowest score, a 39, used a text link that blended into the site's background and made the policy hard to find.

Although Forrester didn't identify the names of the Web sites that earned the mediocre or poor scores, the analyst did announce that two of the eight sites, KBkids.com and eToys.com, finished ahead of the rest in all areas evaluated.

Marc Rotenberg, executive director of online privacy watchdog group Electronic Privacy Information Centre, called online privacy the "number one consumer issue". He said online merchants have to do more to convince consumers their private information won't be misused. "The policies generally are very weak," said Rotenberg. "People still don't trust that their information is not going to be abused."