Answer:
Case Study
Explanation:
Case Study -
It is the type of research method , where the in depth investigation about a particular object , person , community or group is done , is referred to as case study.
In this research method , the data and information is collected from various sources available , in order to have a wider range of information .
This research method , is mainly used in the field of psychology .
Hence , from the given example of the question,
The correct term is case study.