The use of mobile devices has led to shorter forms of communication among youth.

The use of mobile devices has led to shorter forms of communication among youth.

The use of social-networking web sites among young Americans continues to climb, with nearly three-fourths of American teens now using these sites. But fewer teens and young adults are blogging now than four years ago, and the number of those who use Twitter is still very low.

These are among the findings of a new study from the Pew Internet & American Life Project, called “Social Media & Mobile Internet Use Among Teens and Young Adults.” Released Feb. 3, the study reveals new trends with implications for schools.

The study found that young people are losing interest in long-form blogging, as their communication habits have become increasingly brief and mobile. Technology experts say it doesn’t mean blogging is going away. Instead, they say, it has gone the way of the telephone and eMail—still useful, just not trendy.

“Remember when ‘You’ve got mail!’ used to produce a moment of enthusiasm and not dread?” asks Danah Boyd, a fellow at Harvard University’s Berkman Center for Internet and Society. Now, when it comes to blogs, she says, “people focus on using them for what they’re good for and turning to other channels for more exciting things.”

Those channels might include anything from social-networking sites to others that feature games or video.

The Pew study found that 14 percent of internet youths, ages 12 to 17, now say they blog, compared with 28 percent who did so in 2006. And only about half in that age group say they comment on friends’ blogs, down from three-quarters who did so four years ago.

Pew found a similar drop in blogging among 18- to 29-year-olds.

Overall, Pew estimates that roughly one in 10 online adults maintain a blog—a number that has remained consistent since 2005, when blogs became a more mainstream activity. In the U.S., that would mean there are more than 30 million adults who blog.

“That’s a pretty remarkable thing to have gone from zero to 30 million in the last 10 years,” says David Sifry, founder of blog search site Technorati.

But according to the data, that population is aging.

The Pew study found, for instance, that the percentage of internet users age 30 and older who maintain a blog increased from 7 percent in 2007 to 11 percent in 2009.

Pew’s over-18 data, collected in the last half of last year, were based on interviews with 2,253 adults and have a margin of error of plus or minus 2.7 percentage points. The under-18 data came from phone interviews with 800 12- to 17-year-olds and their parents. The margin of error for those data was plus or minus 3.8 percentage points.