Is it a survey,observational study ,experiment,repeated measures study,matched pairs study?
It’s an experiment for sure because subjects are being placed into separate groups. There are no repeated measures since everyone is being measured only once after 2 years. It’s not a matched pairs study because subjects are just being randomly assigned to the two groups (there is not attempt to make sure that, for example, a 20 year old in one group is matched with a 20 year old in the other group and a 70 year old in one group has a “match” with a 70 year old in the other group, etc.).
