The child of a science writer I know once hopped into her mother's lap and took control of the family computer. My friend was amazed to watch her daughter, who was 3 at the time, use the wheel on the mouse to scroll down the screen. "Oh," the science writer said, "that's what that does!"

Perhaps John McCain has felt just that kind of wonderment this year, as his staff and family have taught the 72-year-old Arizona senator how to browse the Web and read his daughter Meghan's campaign blog. The Republican nominee has described himself as a technological "Neanderthal" and computer "illiterate." And now his Democratic opponent has turned those comments into a campaign ad that paints McCain as "out of touch."

McCain earned a little of my sympathy on this point a few weeks back, when work required me to bumble through a virtual world that tested my own online agility. My assignment took me to Second Life, a vivid online community where inhabitants create animated electronic stand-ins called "avatars" to play and do business in a bustling, game-like 3-D environment.

Despite more than a dozen years of working in digital media, my visit to the much-hyped service was humbling. I was able to quickly create a cookie-cutter avatar and then "teleport" to a recruiting center built in Second Life by government officials from Missouri to help fill real-world jobs in the state's technology division. But I was hardly graceful. Using my mouse and arrow buttons, I managed to wander through the state's displays and even collect a free T-shirt to add to my avatar's electronic wardrobe. But I also bumped into walls and struggled to figure out how to make basic moves, like sitting down.

All of this would have been child's play to my nephews, ages 8 and 11, who I've seen master complex new game controllers within minutes of removing them from the package. In fact, the difference between their natural ability and my own klutziness is the difference between what some experts in online learning and behavior describe as "digital natives" and "digital immigrants."

John Palfrey and Urs Gasser popularize the idea of online natives and immigrants in their accessible new book, "Born Digital," although educational game creator Marc Prensky is generally credited with coining the terms. In 2001, he described how technology was rewiring the brains of this generation of children to "think and process information fundamentally differently from their predecessors." Digital immigrants, on the other hand, "adapt to their environment" but "always retain, to some degree, their 'accent,' that is, their foot in the past."

Second Language That accent can be particularly thick when it comes to setting policy, which may explain why government leaders have been so tongue-tied in trying to address critical technology challenges for more than a decade -- from modernizing intellectual property laws and updating security practices to establishing policies that foster competition in telecommunications and increase reliable and affordable access to faster online services. Technology also creates new expectations for transparency and accessibility.

In that context, comments such as President Bush's past musings about "rumors on the Internets" and using "the Google" to view a satellite image of his Texas ranch deepen the divide between the immigrants and natives. Garrett M. Graff, in an essay in The Washington Post last year, argued that the press and the public were being too easy on digitally illiterate politicians in a way that would be unacceptable on questions of foreign policy or macroeconomics. "Why is it," he asked, "that we blithely allow our leaders to be ignorant of the force that, probably more than any other, will drive and define the nation's economic success and reshape its society over the next 20 years?"

Obama's ad mocking McCain's tech savvy offers no such allowance. It aims to make the Republican seem out of step with online immigrants and natives alike by reminding them that he "admits he still doesn't know how to use a computer" and "can't send an e-mail."

In truth, McCain has said he's only made tentative forays into the digital world. He told The New York Times in July about several blogs his wife and staff have shown him -- and he promised he was "learning to get online myself, and I will have that down fairly soon." He described reading messages on other people's BlackBerrys but noted that he "never felt the particular need" to send e-mail messages of his own.

All of that may have sent an entirely unintended message to digital natives. The message to other political leaders: It's time to log on.

Mark Stencel Mark Stencel is editor and deputy publisher for Congressional Quarterly Inc.'s Governing magazine and its Web site, Governing.com.