Answer:
Observation
Explanation:
In a research with people, for example an study inside a classroom, is necessary to give time to the people to be studied to get used of the presence of the researcher, because if not, the students or the teacher is going to behave in a different way, they are not going to talk as they usual do or they are not going to participate in the class as they normally do.
That is the reason why in a social study is necessary several observations to have a wide panorama of how is the "normal" social interaction.
