Think the teenager in your house can out-surf you? Think again. So says a study of 13- to 17-year-olds released Monday by the Nielsen Norman Group. The results suggest that some businesses are using ineffective strategies to target a teen market of some 20 million.

The study found that, contrary to stereotype, teens as a group are not as adept as adults in navigating the Web.

In the study, 38 teens were assigned tasks at 23 Web sites, operated by Apple, McDonald's, Procter & Gamble and other companies and organizations.

At the Web site of the California Department of Motor Vehicles, teens were asked to make an appointment for a driving permit. At MTV.com, the challenge was to discover when Norah Jones would be in concert in the Golden State.

The teens completed such tasks 55% of the time, compared with 66% of adults in a previous study.

The results echo other studies. "There is this notion out there that these amazing multitasking, multigadget kids are running circles around their parents," says Lee Rainie, director of the Pew Internet & American Life Project. "And some of them are. But the out-of-it addled parent is now a pretty Internet-savvy person, by and large."

Immaturity and poor reading skills partly explained the youngsters' lackluster performance, the study concluded. So did the teens' weak research skills and unwillingness to tough it out when a site posed design obstacles.

The study, conducted last fall in California, Colorado and Australia, poked holes in other stereotypes. While teens like cool-looking graphics, Web designers would be wise to keep glitzy blinking graphics and overly stimulating content to a minimum. Teens preferred sites with a cleaner design.

There's a fine line, though, because a site deemed boring is the kiss of death, says Jakob Nielsen, a principal at Nielsen Norman.

How can businesses make their Web sites more teen-friendly? Youngsters typically visit the Web to research products they buy offline. They are drawn to games, quizzes, polls and sites where they can communicate with their peers. They like posing anonymous questions on topics too touchy to ask face-to-face.

"Most Web sites miss the boat," Nielsen says. "If you don't get it right for teenagers, they're gone from your Web site in a split second, and that can cost you a lot of business."

Other findings:

• Some Web site features tend to turn off teens: complex or incomplete content, long downloading times and confusing navigation.
  
• Teens tolerate ads more than adults, though overkill is a risk.
  
• Teens tend to be apprehensive about downloading plug-ins and clicking on unknown links. The main reason: They fear viruses.
  
• The word "kid" is a teen-repellent.