สำมะโนธุรกิจและอุตสาหกรรม พ.ศ. 2565 อุตสาหกรรมการผลิต: ปริมณฑล

61 Appendix A: Sample Design 1. Establishments with 1 – 10 persons engaged The stratified systematic sampling was adopted for the survey. Bangkok and each province were constituted a stratum. Each Thailand Standard Industrial Classification (TSIC 2009) and sub-size of establishment was constituted a sub-stratum. The sample unit were establishments. 1) Stratification Bangkok and each province were constituted a stratum. There were altogether 77 strata. Each stratum was classified by TSIC 2 0 0 9 into 818 sub-stratum at 409 activity levels and in each sub-stratum was divided into 2 sub-sizes according to number of persons engaged: 1 – 5 and 6 – 10. 2) Selection of Sampling Unit The sample selection of establishments was done by systematic sampling and performed separately and independently in each sub-stratum and sub-size. The total selected sampling unit were 49, 9 5 2 establishments from total 398,645 establishments. Appendix A: SAMPLE DESIGN