How many hours per day does the average U.S. citizen spend online?

Answer 1

According to MediaMetrix, "Americans spent an average of 77 minutes online and viewed an average of 50 different web pages per usage day during August", however there is no date associated with this data (source 1).

According to the Stanford Institute for the Quantitative Study of Society (SIQSS):
"the average Internet user spends 3 hours per day online, almost double the 1.7 hours the average respondent spends watching television.
Data were collected from a representative sample of 4,839 American respondents between the ages of 18 and 64 in June 2004." (source 3)

University of California, Berkeley's How Much Information 2003 research found that:
"The average global Internet user spends 11 hours and 24 minutes online per month, according to Nielsen/NetRatings. The average user in the United States spends more than twice that amount of time online: on average, 25 hours and 25 minutes at home and 74 hours and 26 minutes at work." (source 4)

According to Year Three of the UCLA Internet Report:
2002: 11.1 hours per week
2001: 9.8 hours per week
2000: 9.3 hours per week
(source 2)

Answer 2

I have a problem with the data stated above. It only takes into account Internet users . Not all households have a computer. Also by online are you including work or just personal use? Does the data take into account school usage?