Practice Exercise 1. 2. 3. Differentiate between simple random sampling and stratified random sampling. Suggest a research topic for comparing the marketing strategies of two bathing soaps, and plan a sampling technique for this research. Discuss the merits and demerits of secondary data obtained from government records and from syndicate sources. The relationship between self-esteem and test performance 4. 5. 6. 7. 9 Design an experimental study to investigate these variables. What is your hypothesis? What is your independent variable? What is your dependent variable? How will you make sure that the study has high internal validity? Will you use random assignment to conditions? Do any ethical concerns about the treatment of participants emerge from your experimental design