为了进行一项研究，有一个至关重要的要求，选择的样本人群的采访问题要问。与定量研究不同，抽样主要采用定性研究方法。研究论文通常从较大的群体中随机抽取样本。本样本用于对研究问题或问题进行研究。本研究采用有目的抽样。有目的抽样就是选择样本人群，使告密者与研究真实地联系起来。考虑告密者的社会地位、居住地、文化、收入等特征(Wu， & Lam, 2016)。
For conducting a research, there I s a vital requirement for choosing the sample population to whom the interview questions to be asked. The sampling is mainly done in a qualitative research method, unlike the quantitative research. The research paper usually chooses a random sample that is taken from the larger population. This sample is used to conduct the study of the research question or issue. In this research study, purposive sampling is used. Purposive sampling is nothing but choosing the sample population in such a manner that the informants are related to the study in the true way. The characteristics of the informants such as social status, area of residence, culture, income etc are taken in to consideration (Wu, & Lam, 2016).
In this study, the sample population is the people in China, who are hailing from middle class family. It is taken in such a way that either of the one relative of these people are in abroad. This will let me the researcher know whether there is a possibility of the informants to avail the medical care from abroad when they find the health care service and support in China is expensive and low efficient. This is the main study of this research. The reason to the sample from middle class patients is to judge the affordability of the Chinese medical care in the public domestic hospital among the middle class people. On a research, it is mainly seen that a larger population from this category of people have found the treatment expenses unaffordable. Seeing a doctor is even more expensive in China.
The informants are mainly the Chinese patients who have already travelled to US fro better treatment. The qualifying informants include all those people who travelled to US for the purpose of availing treatment. Not necessarily, they have taken any treatment or operation or diagnosis or recovery treatment. The trigger that made them to travel to USA is mainly assessed in the interview with these informants. There are mainly three informants selected as sample. In order to get a proper information and to avoid bias, a doctor in Boston who used to be a doctor in Chinese public hospital is also one of the three informants. The main aim of the researcher is to finalize such informants who are from different background but related to the given situation. By this, there will be no bias for the selected sample. The sample to be selected in such a manner that informants have the experience to the given scenario. Here, when the informants are mainly three Chinese patients who travelled abroad and Here, based on the agency theory, the response from both the sides, being a patient and a doctor is considered so as to come in a proper and valid conclusion and analysis. The internal aspects of the operations and functioning of Chinese hospital can be known from the doctor who worked there. The approach to the patients and the way the treatment is given to the patients along with expenses details are known from the other patient informants.