Draw lots:
Mark each unit in the group with numbers, make a label, put it in a container, and randomly select n labels as samples. The lottery method is simple and easy, which is suitable for the situation of small overall capacity.
Random number table method:
Use a random number table for sampling. Firstly, a random starting number is determined, and then N numbers are extracted according to the numerical order in the table, and the corresponding unit is the sample. The random number table method is simple to operate, but when the overall capacity is large, the same unit may be extracted repeatedly.
Computer random sampling:
Computer program random sampling. First, input the total capacity n and the sample capacity n, and the computer program will automatically generate a random sample. Computer random sampling is fast and suitable for large-scale census.
Method of drawing lots:
Mark each unit in the group with numbers, knead it into balls, put it into a container, and randomly select n balls as samples. The lottery method is similar to the lottery method, which is suitable for small overall capacity.
Random sampling method:
Randomly select a starting unit in the population, and then sample it according to certain rules (for example, every k units). Random sampling method is suitable for situations with large overall capacity and certain regularity.
System sampling:
Arrange the units in the group in a certain order, starting from the first unit, and take one unit from every k units as a sample. Systematic sampling is suitable for situations with large overall capacity and certain regularity.
Stratified sampling:
Divide the population into several levels, and randomly select a certain number of units from each level as samples. Stratified sampling is suitable for situations with large overall capacity and distinct levels.
Cluster sampling:
Divide the crowd into several groups and randomly select a certain number of groups as samples. Cluster sampling is suitable for situations with large overall capacity and similar group characteristics. Randomly select a starting unit in the population, and then sample according to certain rules. Random sampling method is suitable for situations with large overall capacity and certain regularity.
System sampling:
Arrange the units in the group in a certain order, starting from the first unit, and take one unit from every k units as a sample. Systematic sampling is suitable for situations with large overall capacity and certain regularity. Stratified sampling divides the population into several grades,