How to take samples during production?

1 random sampling (lottery method, random sampling table method) is often used when the population is small, and its main feature is to extract one by one from the population; Advantages: simple and easy to operate Disadvantages: the overall size is too large to be realized.

2. The main characteristics of stratified sampling and stratified proportional sampling are mainly used for people with obvious differences in individuals. * * * Similarity: the probability of each individual being drawn is equal to n/m.

3 systematic sampling

When there are many individuals in the group, it is more troublesome to adopt simple random sampling. At this time, the population can be divided into several balanced parts, and then an individual can be extracted from each part according to predetermined rules to get the required samples. This kind of sampling is called systematic sampling.

It depends on the specific situation such as the output you produce.