Random sampling of sampling method

(lottery method, random sample table method) is often used when the total number is small, and its main feature is to extract one by one from the total number;

Advantages: simple operation.

Disadvantages: The overall scale is too large to realize (1) lottery.

Generally speaking, the lottery method is to number n individuals in the population, write the numbers on the digital labels, put the digital labels into a container, stir them evenly, extract one digital label from it every time, and extract it continuously for n times to get a sample with a capacity of n.

(The lottery method is simple and easy, suitable for a few people in the crowd. When there are a large number of individuals in the group, it is difficult to "evenly mix the group", which is probably due to the poor representativeness of the samples produced by lottery)

(2) Random number method

In random sampling, another commonly used method is random number method, that is, random number table, random number dice or computer-generated random number are used for sampling.