The researchers note that their findings represent the subjective views of teachers and should not be seen as definitive proof that widespread use of computers, phones and video games affects students’ capability to focus. Even so, the researchers who performed the studies, as well as scholars who study technology’s impact on behavior and the brain, say the studies are significant because of the vantage points of teachers, who spend hours a day observing students.

Scholars who study the role of media in society say no long-term studies have been done that adequately show how and if student attention span has changed because of the use of digital technology. But there is mounting indirect evidence that constant use of technology can affect behavior, particularly in developing brains, because of heavy stimulation and rapid shifts in attention.

But nearly 90 percent said that digital technologies were creating “an easily distracted generation with short attention spans.

The report by the NEA, a taxpayer-funded independent federal agency, is based on reading trends data collected from more than 40 sources, including other federal agencies, universities, foundations, and associations.

On average, Americans ages 15 to 24 spend almost two hours a day watching TV, and only seven minutes of their daily leisure time on reading.

In 2002, only 52 percent of Americans ages 18 to 24, the college years, read a book voluntarily, down from 59 percent in 1992.

Although teachers see a number of advantages in young people's heavy use of digital media (especially in their ability to find information quickly and efficiently), it is the potentially harmful effects that have families, educators and policy makers worried. New York Times' Matt Richtel summarizes these concerns in an article about the studies: "There is a widespread belief among teachers that students' constant use of digital technology is hampering their attention spans and ability to persevere in the face of challenging tasks.