The purpose of this research is to assess the sampling procedure and some of the data collection procedures used by the A. C. Nielsen Company in the conduct of television viewing surveys in the United States. The methodology followed in making these assessments is described and explained in the following section.
Three specific aspects of the sampling process and data collection procedure used by the A. C. Nielsen company are assessed The first aspect assessed in the company's sampling procedure. Sample size, sample selection, sample participation, and sample validity are issues that are assessed. The second aspect assessed is the company's data collection procedures, with a specific focus on the tasks that the company demands be performed by the members of the sample. The implications of the company's demands on the reliability of the data collected are assessed.
The terms "validity" and "reliability" are pertinent to the assessment of the company's sampling process and data collection procedure. The quality of any statistical analysis can be only as good as is the quality of the data upon which it is based; thus, the reliability and validity of data collected for use in statistical analysis is of paramount importance. Validity refers to the extent to which data or a data collection instrument measures what it is actually desired to measure, or the extent to which a sample that claims to be representative of a population actually is representative of that population. Reliability refers to the accuracy and precision of a data collection procedure. Validity, thus, is the extent to which differences found through a particular data collection procedure reflect true differences among those variables being measured, while reliability refers to the capacity of an instrument to yield similar measurements under similar conditions.
The reliability of a data collection procedure is a contributor to the validity of that proced...