Online Program

Using GIS to inform sample design for a retail establishment survey

Keywords: sampling establishments, sample design, geographical sample distribution, GIS, Synar

All States and have been required for over 15 years to perform annual inspections of tobacco retail outlets to assess the rate of illegal sale of tobacco products to minors. Furthermore, the federal regulation (Synar amendment) requires that these inspections be carried out on a random sample of outlets. This presentation focuses on the use of GIS to assist in the Synar survey sample design, evaluation of the results, and improvement of design from one year to the next. A few States use area designs but most use list frames and even in these cases the maps can prove very useful and informative for all phases of sample design, implementation, and analysis. We will show how GIS is a potent tool for checking for representativity of the sample by comparing the geographical distribution of the sample with that of the population. We also show how GIS can be used to compare the sample for a given State across time and to present an overall national image of how the sample of outlets is distributed.