Romenesko gets new details on a regular report issued by Howard Polskin’s “one-man research firm” The Tab Farm, which charts what passengers are reading on New York’s subways. (Or at least on the R, N and W trains in mid-town Manhattan). The number of people reading real books on the train seems to hover between 15 and 20 percent. And, as you might expect: tablet, smart phone, and e-reader usage has jumped hugely over the last three years.

Peeking at one of Polskin’s “Mobile Media Consumption Reports” from October 2009, I see that just 1 percent of riders were using e-readers, while in his 3/5/2012 report e-reader usage is up to 6 percent. Given the size of the sample, the numbers fluctuate significantly from week to week, but Polskin cleverly trumps this as real news. (“Magazines and books posted 3% gains in usage.”) But there is at least one definitive fact in the survey: “For the record, I have not seen a Discman or Walkman in the more than two years I have been recording this information on and off,” he writes.

How does Polskin do it? The reports, he says:

… are based on my own observations during my daily commute to and from work. In the morning I get on the subway at 60th and Third in Manhattan and I take the R, N or W train two stops to 57th and 7th. The train is a pretty good cross section of New York City commuters because it’s coming from Queens and it picks up more affluent riders at the first stop in Manhattan. I do the reverse commute at the end of the day. I try to record all media consumption activity I observe in two cars. If the car is too crowded, I settle for just one car. I have a small clipboard where I record the consumption by hand (breaking it down by day and morning and evening). A few people have actually stopped me when I’m doing my research and asked if I’m recording the way people are using their devices.