1. Official data are mainly statistics of preschool education of relevant government departments, including policy documents, government public information, annual reports, census data, etc. The official data of preschool education can be found on the official websites of People's Republic of China (PRC), China Ministry of Education, National Bureau of Statistics and un comet.
2. Industry data refers to a group of companies that provide similar or similar substitute goods or services. By analyzing the market size, trading volume, supply and demand index and development trend of the industry, we can understand the development trend of the industry. The websites that collect the professional data of preschool education are: China Industry Research Network, Zhiyan Consulting, Prospective Industry Research Institute and China Industry Data Analysis Network.
3. Academic research data mainly refers to the data involved by domestic and foreign scholars in the research of related directions, which can be mainly collected on academic websites such as HowNet, Wanfang, VIP and official website of the school library.
4. Survey data refers to the data compiled according to the survey results through questionnaires and interviews.