There are different ways to gather information that will provide answers in the various research questions posed in a social-scientific study. One possible way to obtain data systematically and objectively is through personal or face-to-face interviews, by means of structured and standardized questionnaires. In this type of survey research, the interviewers play a significant role in guaranteeing the quality of the data that they gather through various interviews. Therefore, we believe it to be crucial that they are properly trained before starting their work in the field. With this paper, we attempt to give some insight into the different rules of interviewing that should be taught during the interviewer training. In addition, we emphasize why it is so essential to follow these rules with great precision.