Report: Americans still glued to their TVs by Dan Mitchell @FortuneMagazine May 4, 2012, 2:43 PM EST E-mail Tweet Facebook Google Plus Linkedin Share icons FORTUNE — Americans, unsurprisingly, are still glued to their TVs, according to Nielsen. And when the ratings outfit says “TVs,” it means just that: television sets. We’re still watching an average of 5 hours of video a day — 98% of it on a TV set connected to cable or satellite (or an antenna), as opposed to on a computer or mobile device, according to Nielsen’s “Cross Platform Report,” issued Thursday. That includes on-demand programming and shows channeled through a DVR, but not that beamed to a TV set from the Internet via a computer. But Americans are also “shifting to new technologies and devices that make it easier for them to watch the content they want whenever and wherever is most convenient for them,” says the report. “As such, the definition of the traditional TV home will continue to evolve.” MORE: Why did Target boot Amazon’s Kindle? How quickly it evolves will depend in part on how far programmers, cable companies and satellite providers go to wall off video content sent to computers and mobile devices via the Internet. Many services such as HBO GO require viewers to be cable subscribers. There are reports that Hulu, which is owned by Comcast CMCSA , News Corp. NWSA , and Disney DIS , might soon start demanding “authentication” from viewers in at least some circumstances. That means they’d have to prove they are signed up with a cable or satellite provider before they could watch certain programs. Nielsen found that in the last three months of last year, the average American with a television set watched 153 hours and 39 minutes of television, about 46 minutes less than the year-earlier period. But that counts “traditional TV” only, not viewing on computers or mobile devices. “Traditional TV” also excludes programming that doesn’t come in through a cable or antenna, so people who beam streamed Netflix NFLX shows to their TV sets aren’t counted as “traditional” either. At what point do these definitions become arbitrary? MORE: Netflix’s terrible, horrible no good, very bad week TV watching, in total, appears to be rising, not falling. Which is remarkable (and perhaps depressing, depending on your point of view) given the rise in non-television Internet use, video game playing, and other entertainment options.