Answer:
1. option B
2. option A
3. option D
Explanation:
1. Which of these studies is an experimental study?
Yes, you got it right, it is study 2. Study 1 and 3 are just observational studies, where researchers collect and interpret data based on what they have seen, heard or observed. But for the experimental design, there is a manipulation on the part of the researchers where he grouped them and administered treatments.
2. Study 1 employs a retrospective design.
You also got that part right, Study 1 actually employed the retrospective design by sampling individuals and then collecting information about their past which in this case is asking questions about the participant's dietary and exercise habits between ages 15 and the present and also their medical records.
3. Study 3 employs a prospective design
You also got this right. Study 3 actually employed the prospective design by sampling individuals and follow them over time and data about them is collected as their characteristics or situations changes and in this context, they observed even after a change by sleeping more than 8 hours per night, students still did not seem to experience additional health benefits.
