Reference no: EM133703317
Assignment:
Let's imagine there was a researcher who thought that daily flossing could help people live longer. She conducted a panel survey (panel survey just means the survey was conducted with the same people over many years) over 25 years of 100,000 people (let's assume the data collection was done rigorously and carefully). She recruited people at dentist offices. She found that people who flossed daily lived on average 6 years longer than people who didn't floss.
Dental companies like Delta Dental started hyping these findings in the following way:
1. The researcher found that "people who flossed daily lived on average 6 years longer than people who didn't floss." Is that a causal statement, or a statement about a correlation?
2. What is the causal claim the dentist ad is making?
3. What do you think is the dental company's theory for why flossing leads to living longer?
4. What is the independent variable?
5. What is the dependent variable?
6. What might be a confounding variable to this study? (Remember, a confounding variable is something that is affecting both the independent variable and the dependent variable, and leading to a spurious conclusion.)
7. Is reverse causality a concern for this study? If so, in what way?
8. Is selection bias a concern for this study? If so, in what way?
Optional questions:
9. The study described above is an observational study. Remember, that means the researcher is simply observing the world, and observing people who behave differently.
An experimental study would allow us to make stronger causal claims. What would be some of the ethical considerations for an experimental study?
10. Let's imagine you decided the ethical considerations were outweighed by the value to knowledge. How would you design an experiment to test whether flossing caused longevity?