1. Who/what comprised the sample studied?
2. How many people/elements were studied?
3. What was the target population?
4. Was this an appropriate sample for testing the hypotheses and/or answering the research questions? Why or why not?
5. What was the sampling frame? What are the advantages of the sampling frame used? What are the disadvantages?
6. What was the sampling method (i.e. how did the researchers recruit participants)? Was it an appropriate sampling method? Why or why not? What are the advantages and disadvantages of the sampling method used?

https://link.springer.com/article/10.1007/s11469-018-9940-6