s the interviewees are required to answer in person, the interviewees may feel concerned about the lack of privacy, especially for some sensitive questions, such as the evaluation of students’ ability in the training company, which may make the interviewees avoid or fail to answer truthfully.

The interview survey has a flexible aspect, but it also increases the randomness of the survey process. The answers of different interviewees are various and there is no unified answer. Therefore, the processing and analysis of interview results are more complicated. (Cacciattolo, 2015).

Reliability and Validity
Because the interview process is fast, the respondent often cannot think for a long time when answering the question. Therefore, the answer is often the spontaneous response of the respondent. This answer is more realistic, reliable, and rarely disguised or faked (Menezes, 2012).
Since interviews are often face-to-face conversations, there are fewer respondents and higher response rates. Even if the respondent refuses to answer certain questions, he can get an overview of his attitude towards the issue.

How to collect and analyse the data
The interview survey is an exchange conducted between the two parties. Due to ethical considerations, recording will not be performed on the spot. The collection of data can only be recorded by paper and pen. Record the conversation as completely as possible to avoid missing important information. The processing of the results is also as uniform as possible. To find common ground, must also pay attention to the new information. (Cacciattolo, 2015).

3.4.4 Focus Group