1. Sampling Objectives and Sample Definition: Determine the objectives of the study, the type of samples needed, and how to define the samples, such as sampling a specific group of people, the timeframe, and so on.

2. Definition and Characteristics of the Totality: Ensure that there is a clear understanding of the scope and nature of the totality, including the size, distribution, and characteristics of the totality.

3, the establishment of the sampling frame: to establish a list or frame containing all the individuals in the aggregate, in order to sample from it, to ensure the completeness and coverage of the aggregate.

4. Selection of sampling method: select appropriate sampling method according to the research objectives and resources, such as simple random sampling, systematic sampling, stratified sampling and so on. Big data (bigdata), or giant data, refers to the amount of information involved is so large that it can not be achieved through mainstream software tools, in a reasonable period of time to capture, manage, process, and organize the information to help business decision-making for more positive purposes.