Sponsor areas are not limited to the 57 largest DMAs. Thus, the complete frame for the study was the combination of the largest DMAs and any portion of the sponsor areas that fell outside the 57 largest DMAs.
To facilitate comparisons across years, the national results were based only on data collected from respondents from the 57 largest DMAs. Data collected from respondents not in the 57 largest DMAs, but in a sponsor area, are not included in this analysis. Some of the 57 largest DMAs are also included in the sponsor areas and therefore were oversampled. The data from these respondents (as well as from the other respondents in the 57 largest DMAs) received an appropriate weight in the analysis in order to generate valid national results and facilitate comparison with data from other years.
The sample was stratified by area and within an area by publicity category. Each sponsor area is also further stratified by large versus non-large DMA as well as any stratification requested by the CEE member funding the oversample.10 The CEE members who fund the oversample for a sponsor area determine the total number of sampling points allocated to the sponsor area as a whole. This total number of sampling points is then allocated across sponsor area strata proportional to population. Among the top 57 DMAs, for areas located outside the sponsor area, each publicity category was allocated approximately 333 sampling points. In order to achieve the target number of sampling points, a larger sample was selected to receive the survey to allow for non-response.
A list of the large DMAs and their publicity category assignments is provided in the table below.11 A list of the DMAs included in the sponsor area and their publicity category assignments follows. Lastly, the large DMAs and the DMAs in the sponsor areas are shown on a map along with their publicity categories.
10 11 No CEE member funding an oversample requested additional stratification. Between September 2008 and 2009, 2 of the 57 largest DMAs changed publicity category: Tampa-St. Pete (Sarasota) and Charlotte. Both changed from “Low” to “Other”.