Pick one of the following research scenarios. Identify one or more potential variables and suggest a sampling method for collecting the required data.

1. A business has a new product they plan to release and wants to get information on how potential customers react to its design.
2. A sociologist wants to collect information on how people's opinions change after viewing a video presentation.
3. A medical researcher is planning a study to investigate the effectiveness of a new drug and needs to find people to participate in the study.
4. A city planner wants information on how the length of green lights effects the number of people who run the following red light.
5. A historian wants to collect information on birth rates during the depression era.
6. The owner of a website wants to know how the visitors to the website feel about the latest opinion essay posted on the site's home page.