The basic procedure of sampling includes the following steps:
Define population and sampling frame. First of all, it is necessary to clarify the overall scope of the research object, establish a sampling framework, and determine the sample source and sampling method.
Determine the sampling method. According to the characteristics, research purpose and sample size of the research object, select appropriate sampling methods, such as simple random sampling, stratified sampling and cluster sampling.
Determine the sample size. Sample size directly affects the estimation accuracy and confidence level, and needs to be determined according to factors such as population size, variance and sampling method.
Take a sample. According to the sampling method and sample size requirements, samples are extracted from the sampling box, and their related information, such as sample number, gender, age, etc., are recorded. , are recorded.
Collect sample data. Collect sample data through field survey, questionnaire survey and experiment.
Data analysis and inference. The collected sample data are statistically analyzed, the overall characteristics are inferred, and statistical conclusions such as estimated value, confidence interval and hypothesis test are given.
Conclusion and report. According to the data analysis and inference results, draw a conclusion, and write a report or paper to explain the research problems, methods, results and significance.
In a word, sampling is a systematic process, which needs to be carried out in strict accordance with basic procedures, and attention should be paid to controlling sampling error and data quality to improve the reliability and effectiveness of research.