These complex studies combine several methods of research including: in-depth interviews, informal discussions and observation.
The survey participants are usually people who share a particular space or interest, there are certain relationships between people (couples, families, employees, etc.)
The method involves visiting environment in which the participants live because the context in which they operate is important and should be taken into consideration.
The case study comes close to real life of the subjects, trying to find answers to questions apprently simple, but complicated essentially, like "why" or "how?". Case studies help us to understand the behavioral phenomena that can be seen in its natural environment.
The recommended number of case studies - three or four per segment.