Television

Nielsen ratings work by two major ways.  Set monitors for large networks (top 56), only monitors TV's, and smaller networks (56 and above) use diaries to log entries.

This rating system is a brilliant measurement device for the television industry, and similar rating are used for radio as well.  For that reason alone, Nielsen has a pretty recession prove job.  With that said, these ratings are as accurate as can be presently, however, they really aren't that accurate for a numerous different reasons.

Large networks using the people meter are faulty because you cant tell how many and who exactly are watching the television set.  The entire reasoning behind rating system is to measure audience as well as who the audience is so advertisers can better invest.

Smaller networks use diaries, which seem to allow them to better account for their viewing habits, especially if they watched the show via streaming or away from the house, however as true as any hand written assignment, it is human nature to hide things and take their sweet time to journalize their assignment which leads to non-factual results.

If this wasn't enough issues of accuracy, Nielsen does "sweeps", which is done quarterly (4 times a year) and the television networks know this.  Therefore, we get jacked up programs in order to bring more viewers in and drastically alter the ratings for the benefits of the networks.

These are the problems with Nielsen ratings system, however we live in an imperfect world, thus these rating will have to do until through trial and error we find better ways to measure audiences.  One suggestion I would add is to work with cable providers and incorporate a device inside the new smart TV's to see what is being watch, to include DVR, so you could get a lot broader of an sample instead of only 9,000 Americans.  Yes the same issue would pertain, however, we might get a little more insight because the sample size is larger.