A case study is a process or record of research into the development, it is also defined as a particular instance of something used or analysed in order to illustrate a thesis or principle.

Picking a case study is a key part of the research process, therefore, when deciding on case study, one has to consider the Project Topic that is being researched.
A case study that is not in line with the topic may lead to wrong conclusionis and results.

Example, when researching about student performance, the case study must fall in a school environment. This serves as a good ‘case’. Anything outside the school environment may lead to wrong results and conclusions

A topic that details Employee performance, also requires a corporate environment as case study, and data collection methods like questionnaires are applied