Answer:
Observation data
Explanation:
Observation or observational data, which is defined as the valuable form of research, that provide the information to the researchers goes beyond the statistics as well as numbers.
In short, it is the systematic way or method, in which the data is collected or gathered through observation the people in natural settings or the natural situations.
So, in this scenario, Nielsen Media Research (NMR), uses the people meter which is linked with the TV sets and transmit the information to NMR. Therefore, they are using the observation data while collecting the information.
