Final answer:
Case studies are an in-depth qualitative research method used to understand specific individuals or groups within their environment. They offer detailed insights but often have limited generalizability to the larger population. Threat analysis is important for validating case study findings, and they are subject to ethical considerations and IRB approval.
Step-by-step explanation:
Case studies are a qualitative research method used to examine complex phenomena within their contexts, especially when the boundaries between phenomenon and context are not clearly evident. They allow researchers to investigate individuals or groups in natural settings, giving a depth of understanding to the specific case in question. Threat analysis is a critical aspect of ensuring the internal and external validity of a case study. This involves assessing potential threats that may challenge the legitimacy of the findings. Contrary to some misconceptions, case studies are not limited to legal action scenarios (‘B’ is incorrect) and are widely used in research to test theories or validate new methods in practical settings, as mentioned in option (‘D’). The claim in (‘C’) that case studies are never applied in research is also incorrect.
While case studies provide comprehensive details and insights, their scope is sometimes too narrow to allow for generalization to a larger population. Nonetheless, they are valuable for identifying opportunities for further investigation and for filling in research ‘blind spots’. Ethical considerations are paramount in case study research, particularly when involving human subjects, and typically require approval by an institutional review board (‘IRB’).