The study, conducted by the Stanford Institute for the Quantitative Study of Society, assesses the social consequences of Internet use among a large portion of American households, including Internet users and nonusers.
The key finding of the study is that "the more hours people use the Internet, the less time they spend with real human beings," said Stanford professor Norman Nie, who was one of the principal investigators of the study.
The crux of the study, that people who engage in heavy Internet use are increasingly isolated from others, runs counter to the assertions by some Netizens, who maintain that the Internet brings them closer to a greater number of people through electronic relationships. Net enthusiasts claim that they can find people with similar interests through discussion groups and communities and that they also stay in better touch with friends and relatives through email.
"Email is a way to stay in touch, but you can't share a coffee or a beer with somebody on an email or give them a hug," Nie said.
But others contend that the Internet is just a small part of a vast landscape of media that people use in their lives, with each method having its own merits.
"We have now added the Internet on top of the fax, the phone, the post and face-to-face as a method of communications," said Steve Jones, professor of communications at the University of Illinois at Chicago. "I have seen studies and done studies that show that for particular groups of people, like senior citizens, the Internet has been incredibly positive, allowing them to communicate much more frequently and in richer ways than they have been."
Nie used a company he co-founded, InterSurvey, to conduct the survey over the Internet. Stanford is an investor in the company, and Nie serves as chairman of its board.
InterSurvey is in the process of giving away Internet devices and connections to several hundred thousand households in exchange for their participation in surveys and marketing studies. So far, the company has built a panel of about 35,000 participants; the Net use study queried 4,113 adults in 2,689 households.
Jones, who also is the founder of the Association of Internet Researchers, a scholarly think tank devoted to Internet research, questions the methodology of the study, as it is based solely on a sampling of people who have received devices and Internet connections from the surveyors.
"To be able to extrapolate to all American households from an Internet-only survey boggles my mind," Jones said. "I would like to ask questions about the methodology and about the academic validity and scholarly quality of the study."
About two-thirds of those surveyed who have Internet access said they spend fewer than five hours a week on the Internet and did not report major day-to-day behavioral changes. But the other 36 percent, who use the Internet five hours or more a week, reported significant changes in their daily lives, including less time spent face-to-face with friends and family or watching television, the study said.
"Internet time is coming out of time viewing television, but also, at the expense of time people spend on the phone gabbing with family and friends or having a conversation with people in the room with them," Nie said.
The study's other preliminary findings include:
The more years people have been using the Internet, the more hours they spend on it now.
A quarter of the respondents who use the Internet regularly (more than five hours a week) feel that it has reduced time spent with friends and family or at events outside the home.
A quarter of regular Internet users who are employed say the Internet has increased the time they spend working at home without cutting back at the office.
Sixty percent of regular Internet users say the Internet has reduced their TV viewing, and one-third say they spend less time reading newspapers.
The least educated and the oldest Americans are least likely to have Internet access, but when they do use the Internet, their use is similar to others' use.
Nie, who has in the past also researched the decline of Americans' involvement in politics and community organizations, said that few studies have looked at the potential psychological and emotional effects of "more people being home, alone and anonymous." People express more concern about the invasion of privacy on the Internet, he said.
The study also points to some other outcomes from increasing Internet usage.
"Those who use the Internet also report spending fewer hours caught in traffic, fewer hours in shopping malls," said Lutz Erbring, a professor at the Free University of Berlin and a co-investigator of the study.