Science Public Policy Analyst
A case study is a description of a particular type of social condition, organization, group, or individual. Generally, statistical data provides stronger evidence than individual case studies. For example, to demonstrate the problem of unemployment in your city, one would want to know the statistical rate of unemployment provided by the US Department of Labor. However, a case study might shed some additional insights into the actual effects of unemployment on a typical family. Therefore, never use case study data as a sole source of evidence in doing PPA. If you use them at all, include a reference to a case study to supplement statistical data.