Determine whether the study is an observational study or an ex...

Question

Determine whether the study is an observational study or an experiment. Explain.

Researchers conduct a study to determine whether a medication based on fish oil known as omega-3 carboxylic acids is effective in reducing the risk of cardiac events in people already at risk. In the study, 13,078 patients are randomly chosen to receive either omega-3 carboxylic acids or a placebo of corn oil daily. Researchers compare the number of cardiac events of the two groups over similar follow-up periods of time. (Source: American Heart Association)

Accepted Answer

Welcome back, everyone. In this problem, researchers wanted to find out whether a new herbal supplement could improve memory retention in adults. To test this, they randomly assigned 600 participants to receive either the supplement or a placebo daily for 6 months. At the end of the study, they compared the memory performance of both groups using standardized tests. Is this study an observational study or an experiment? Explain. A says it's an experiment because it involves comparing two groups without altering variables. B says it's an experiment because researchers control the assignments of treatments. C says an observational study because they only compare memory performance. And D an observational study because participants are not selected based on memory performance. Now, to determine whether it's an observational study or an experiment, let's first define the two. What's the difference between both of these? Well, recall, OK, that an observational study involves observing subjects without altering any variables. So an observational study is really an observation, OK, without any form of intervention. You're not changing anything, you're just allowing the, the, the, the group to perform under their natural uh tendencies. On the other hand, in an experiment, OK, you still observe, so it's still an observation. But you intervene, you make changings. It, it involves deliberately, sorry, I should say with it involves deliberately manipulating one or more variables to determine their effect on the outcome. So it's really an observation with intervention. So know which one of these is our situation here. Well, in the study, notice here it says that they're randomly assigned, OK, they are randomly assigned 600 participants. So we know that in this case. It was random to receive either the supplement or the placebo. The researchers control which group receives the supplement, and that indicates manipulation of the treatment variable. We also told here that at the end of the study they compared the memory the memory performance of both groups using standardized tests, OK? So since they actively intervened by assigning treatments, this makes it an experiment. Therefore, the study is an experiment because researchers manipulate the treatment by randomly assigning participants to either the supplement or placebo group. B is the correct answer. Thanks a lot for watching everyone. I hope this video helped.

Key Concepts

Observational Study vs. Experiment

Random Assignment

Control Group

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