Simple random sampling is generally used for cluster sampling, right?
Simple random sampling, also known as simple random sampling, refers to randomly selecting n units from the total number of n units as samples, so that the probability of each sample being selected is equal. Simple random sampling can be done by tossing a coin, rolling a dice, drawing lots, looking up a random number table, etc. Simple random sampling is suitable for cases with few overall units.
Cluster sampling, also known as cluster sampling, is to divide all units in the population into several sets that do not cross each other and do not repeat each other, which is called cluster. A sampling method in which samples are sampled in groups. Cluster sampling requires that each cluster has good representativeness, that is, the differences between units within the cluster are large and the differences between groups are small. Because the group is usually composed of those units that are geographically adjacent or belong to the same system, the survey sites are relatively concentrated, which not only saves the survey cost, but also facilitates the implementation of the survey.