I’ve spent the past week filling in my Neilsen Ratings diary. It’s been interesting to actually participate in the numbers that have shaped television programming for so many years.

The basic system is simple: for every fifteen minutes that each TV in your house is on, write in the channel it was tuned to, the show that was on, and who (if anyone) was watching. I live alone and didn’t have any guests this week, so it was pretty easy.

What was difficult was dealing with the fact that Neilsen hasn’t caught up with the times. For several years, I’ve had a Dish Network DishPlayer, which has PVR functionality. Like TiVO and Replay, this box completely changes the way you watch television. You no longer care when the station chooses to air a show, and with your favorite programs regularly recorded to disk, you spend less time watching random crap.

Neilsen’s diary can’t cope with this. There’s a single page at the back that lets you write in up to ten programs that you recorded on a VCR or DVD-R, but that’s ten for the entire week. I recorded only 26 different shows last week, and that’s primarily because it was a dull week and I had a lot of anime DVDs to catch up on. And it doesn’t account for the shows that I’d normally save up for a few weeks and then watch all at once.

It was easy for them to add DVD-R recorders to their data, because it fits in with the model they understand: time-shifting as the exception, not the rule. As PVRs increase in popularity, Neilsen runs the risk of becoming irrelevant, and TiVo’s much-hyped ability to count how many people “rewound” to check out Janet Jackson’s nipple shield is not a replacement. TiVo’s data gathering, like WebTV’s before it, is missing the critical data: the number and demographic breakdown of the people watching.