Answer:
Case studies involve intensive investigation of a single topic or event, often including interviews, surveys, and other kinds of structured and unstructured data collection. Case studies provide the opportunity to study a smaller set of variables in depth. Secondary data analysis, on the other hand, involves the use of already-existing data sets that have previously been collected by other researchers. With secondary data analysis, the researcher has access to a large population sample, but they also have much less control over the data collection process.