Panel is still a sample, a subset of a larger population, to which one wishes to make inferences. If data derived from the sample are to be inferred to the population, the question of representativeness arises. Is the UWF/Listener Group Panel representative?

Heads of Households with Telephones
First, the Panel was constructed so as to recruit heads of households having a telephone. Heads of household are often used in survey research because household heads are considered to be knowledgeable of a wide variety of decisions, have a broad base of experience, and so on, which makes them better qualified to answer a broad variety of survey questions. This is particularly important for panels whose members may be asked a variety of questions from one panel administration to another. It is important to note, therefore, that the UWF/Listener Group Panel does not represent the general population, but rather heads of households in the Pensacola having a telephone. (Approximately 98 percent of the households in the MSA have a telephone).

How is representativeness achieved? The sample plan , not sample size, allows one to achieve sample representativeness. Essentially, sample plans describe how elements, or sample units, are drawn from the population. For example, we could “draw” elements by standing on a street corner and asking passersby if they would participate in the panel. This is a type of sample plan (often referred to as the “man on the street” interview). However, this type of plan, part of a number of plans known as “non-probability” sample plans, does NOT guarantee representativeness. Rather, “probability” sample plans guarantee representativeness. A probability sampling plan is one in which every member of the population (defined as heads of households with telephones) has a chance of being drawn into the sample. The UWF/Listener Group Panel was recruited using a probability sample plan known in the marketing research industry as a “RDD Sample.” In this sample plan, computer programs generate lists of randomly selected telephone numbers. The numbers are then screened to eliminate not working (or unassigned) blocks of numbers. By randomly generating numbers, we are assured that everyone in the defined population has a chance of being included in the sample. The RDD sample for this project was supplied by Survey Sampling, Inc.http://www.surveysampling.com/ssi_home.html, a major sampling firm in the U.S. So, in summary, the UWF/Listener Group Panel is a representative sample of heads of households with telephones in the Pensacola MSA.

How can we assess representativeness? There are a number of ways we can assess whether or not a sample, after it has been drawn, is representative. First, are data collected from the sample consistent with known, existing data collected from the population? Second, are data collected from the sample consistent with data collected in other, representative samples of the same population? We attempt to answer both these questions in the following paragraphs.

Next