Almost everyone in GAO probably has worked on a case study at one time or another yet may be unfamiliar with what is meant, methodologically, by a case study.
Case studies done by the Government Accounting Office (GAO) are done to ensure audits of services come back showing due diligence of various government agencies serving the public. 
mnli hypothesis: Case studies done by the Government Accounting Office (GAO) are done to ensure audits of services come back showing due diligence of various government agencies serving the public.  premise: Almost everyone in GAO probably has worked on a case study at one time or another yet may be unfamiliar with what is meant, methodologically, by a case study.