1.What considerations go into a decision whether to use probability or non probability sampling? How does selection of a sample size differ between probability and non probability sample (for example when do you use statistical calculations for determining sample size vs. non statistical methods)?

2.Why is it important to focus on reducing total error in a research project and not just on sampling error? What else, besides sample size, are potential contributors to total error?

3.In your own words, describe how to analyze a cross-tabulated table.