4. 8. When determining sample size, what is the basic difference between a "percent rule of thumb" approach and a \"conventional" approach? What is the confidence interval formula for calculating sample size? Describe all the elements of the formula. What are the disadvantages of using the "all you can afford" approach when determining sample size? What are some of the methods that researchers could employ while estimating standard deviation? Distinguish sampling error from non-sampling error. How can sampling error be controlled? Identify different types of intentional fieldworker errors and the controls used to minimize them. Identify different types of unintentional fieldworker errors and the controls used to minimize them. Identify different types of intentional respondent errors and the controls used to minimize them. Identify different types of unintentional respondent errors and the controls used to minimize them. Dene nonresponse. List three types of nonresponse encountered in surveys