By 1983, Nielsen was dissatisfied with the diary method as national measurement tool.

Lower-rated stations claimed the diary method was inaccurate and biased.

Resilience and vulnerability to daily stressors assessed via diary methods.

In work by Bernsten, the diary method was also applied to the study of involuntary memory chaining.

They argued that because they had lower ratings, those who depended on memory for the diary method the may only remember to track their favorite shows.

Under the diary method, Nielsen families often make their entries days after their viewing occurred, when recollections may not be precise.

Before the People Meter advances, Nielsen used the diary method, which consisted of viewers physically recording the shows they watched.

These results are sometimes at odds with the results generated with the diary method in which listeners were asked to note each change of their radio dial.

To test this idea, Mace set up a diary method study in which participants recorded involuntary memories they experienced during a two-week period, in a diary.

LPM's more accurately reported full range of what programming viewers watched, including what was observed when channel surfing, in comparison to the diary method it replaced.

Stations also argued that if it wasn't low ratings that skewed the diary method, it might also be the new variety of channels for viewers to choose from.

However recent research found that research that focuses on mean levels, between-person differences, and correlations among variables are less likely to be impacted by the difference between electronic and paper diary methods.

Theoretically this should give a much more accurate figure for national projection than the now-departing diary method, which was dependent on the memory of the diary keeper during his or her occasional recording period.

The validity of the diary method requires, however, that patients complete their diaries on the day stated rather than retrospectively, and that the patient's record - for example, of peak expiratory flow - is accurate.

The unrest in the marketplace is brought on by the emergence of the "people meter," an electronic device intended to get data on the viewing of individual household members overnight, unlike the previously used diary method.

Meanwhile, critics of the time diary method say it is biased in the other direction: busy people are too busy to keep diaries, so the method favors the unbusy, a charge Mr. Robinson denies.

The diary method of study circumvents these issues by having groups of participants keep a diary over a period of weeks or months, during which they record the details of everyday events that they judge to be memorable.

During the 1980s, the Arbitron Company was developing the Portable People Meter, or PPM, technology to replace its self-administered, seven-day radio diary method to collect radio listening data from Arbitron survey participants.

According to the agency executives, the networks are achieving the price gains even though people meters are showing a general decline in audience size of about 10 percent for some shows, compared with the viewer levels indicated by the diary method used in the past.

Rantel became an early evangelist for the new PPM method, because Rantel researchers had performed many audits of Arbitron radio diaries during its early years and were keenly aware of the weaknesses of the seven-day radio diary method.

Steven Sternberg, a vice president who heads broadcast research at Bozell, Jacobs, Kenyon & Eckhardt, thinks that the old diary method of counting how many 11-year-old and younger kids watch Saturday morning TV reported too high and that the new "people meter" system is reporting too low.

They were convinced their new method was efficient but still weren't sure whether they would fully depend on the people meter measurement alone or use the people meter sample in a fashion similar to their previous diary method as an addition to the household meter sample to produce viewers per household.