*2.3. Sampling Method*

The survey was conducted with a total of 205 respondents, in which 103 night-market vendors and 102 non-night-market vendors (night-market clients), in order to test the differences between the 2 groups—vendors and non-vendors. The vendor and non-vendor groups were determined by using a random sampling method. The vendor population of the Surin province night market is approximately 142 people (information was given by the market authority). Therefore, the number of surveyed vendors was 103, which was calculated by using the modified Cochran Formula for sample size in smaller populations, desiring a 95% confidence level and ±5% precision. However, other criteria were also set to select the vendor group, including equal representatives of both men and women, as well as age ranges. To make the sample design balanced, the same number of respondents and the same characteristics (i.e., gender and age ranges) were also determined for the non-vendor group.
