Read the background materials for this module and, after doing so, address the following questions in a four-page paper:
1. The sampling frame is arguably the most critical element of a study’s sampling plan. Why is this so?
2. How might a poorly specified sampling frame forestall the research process?
3. Are studies that employ convenience sampling invalid? Please explain.
4. Of the sampling methods presented in this module, which optimize external validity (if this term is unfamiliar, revisit the Module 2 home page)? Please explain.