1.2 Sample Size determination The minimum sample required to produce results at a 95% confidence interval and a ±3% margin of error was determined using the following multi-stage sampling procedure. where n = number of sample required for the survey d = margin of error (3% of proportion) p = sample proportion (here we set the proportion at 0.5, therefore the variance p(1p)=0.25 at the maximum) deff = Design Effect (1.6) Therefore, the minimum sample required at the national level was 1.3 Sampling Method 4 * 0.5 (1-0.5) (0.5 ϰ 0.03)2 * 1.6 = 7,110. Stratified Four Stage Probabity Proportional to Size (PPS) cluster sampling was used. - Main strata: The country was divided into six geographic areas – Northern Hills, Eastern Hills, Middle Dry Zone, Lower Valley, Ayeyarwady Delta and Long Coast. (Figure 3) - First level sub-strata: The population was further subdivided into three sub strata according to the population size of the cities or townships. Second level sub-strata: Urban and rural areas were selected within selected sample cities/townships. 90 ICTs in Myanmar: 2016