Arbitron says it will release the April 2009 monthly PPM report for New York today, a week late, as announced last week. However, the ratings company has found more problems with its PPM data for NYC, ...

PPMの意味その1：濃度や組成を表す単位。mg/L（ミリグラムパーリットル）に変換されることも PPMは主に塩素濃度や大気汚染 ...

Arbitron missing its Portable People Meter (PPM) sample targets in Philadelphia and Houston has been big news in RBR and other radio publications for weeks now – but it hit the Associated Press wires ...