What type of study design (prospective or retrospective) is more appropriate for each of the following.

1. A new disease is affecting a small number of people and scientists urgently need insight about the potential causes

2. A program is being evaluated to assess its worthiness for inclusion in the evidence- informed registry

3. The extent to which the use of e-cigarettes results in an addictive pattern of use is being studied .

4. A funding agency wants to assess the yield from three alternative screening tests.

5. An unusual disease that affects twins is being investigated

6. Evidence is being sought about the causal role of school connectedness inis academic achievement.

7. The role of birth weight in kindergarten readiness is being studied.

8A) A new treatment for multiple sclerosis is under investigation

9. Improved understanding about the causal role of meat consumption in cancer incidence is unded investigation.

10) The role of cigarette smoking in the recurrence of liver cancer is under investigation

11) Improved understanding about a rare form of brain cancer is sought

12) Which approach to helping young children to learn how to read works best

13) The role of physical activity in longevity is being studied

14) What is the relation between Marijuana use and mental health among teens?

15) To what extent does texting while driving increase the risk of an auto accident ?

16) What is the relation between race and academic achievement.