Portable People Meter

[citation needed] Convinced that the concept could be achieved, Mr. Kolessar obtained approval from Arbitron's management to undertake a fast-track effort to determine feasibility.

Facing cutbacks in the defense industry, Martin Marietta agreed to take on the commercial project, relinquishing all rights to the technology they would develop.

Now that Dr. Cohen's idea was a full-fledged project with management support, engineers at Arbitron focused on improving the encoding and detection methodology and miniaturization into a hand-held device.

[5] Arbitron, as well as other firms that provide research and consulting services to radio stations, have begun publishing numerous studies based on analysis of PPM data.

[7] Around 2008, the Spanish Radio Association (SRA) and a number of politicians challenged Arbitron and the PPM's accuracy in measuring minority listening.

[8] Although the makers of the PPM claim that it is more accurate than traditional alternatives like handwritten logs or wired meters, critics have raised issues about its accuracy.

Another sales argument is that the device is immune to human forgetfulness, something that can be an issue in studies that rely on self-reporting by test subjects.