The changing art of measuring TV viewership – Network World:

Nielsen Media Research cannot collect data about what people watch on handheld video-viewing gadgets or from PCs streaming network TV shows. While Nielsen estimates around 90% of TV viewing still happens in homes, it’s this burgeoning 10% that TV networks and advertisers are desperate to delve into.

 “The industry is just dehydrated for this data,” says Bob Luff, Nielsen’s CTO, who oversees the design of the technology used to collect and measure TV viewing habits in more than 40,000 Nielsen homes. “But how do you measure what’s on a video iPod at 38,000 feet on an airplane’s fold-down tray?”