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Challenge 3: How are research studies designed?

Learning Targets:

  • I can consider different ways that scientists design research studies to see if treatments work.
  • I can discuss why treatment recommendations change over time.
  • I can explore confusion related to treatments for COVID-19 rooted in research study design.
Estimated Time: 60 minutes

Types of statistical studies



Answer the following questions and read the explanations to see some differences between observational vs. experimental studies.


Because of the urgency to find effective treatments for patients with COVID-19, many research studies were done simultaneously in the first half of 2020. Next, we will explore conflicting results from studies of one particular drug, hydroxychloroquine, to understand how researchers, doctors, and policy-makers have changed their opinions over time about this medicine.


Widely cited hydroxychloroquine study is ‘flawed’, Fauci tells hearing



Find out

  1. How were the studies designed that concluded hydroxychloroquine was effective? How about the studies that found that it didn’t help?

  2. How has the research cycle of scientific inquiry influenced the medical community’s opinion of the drug over time? Use 3 sources of evidence to support your claim.

Reflect & Discuss

How did policy-makers and government officials add to the confusion surrounding research on hydroxychloroquine for COVID-19? Use 3 sources of evidence to support your claim.


Imagine you are a researcher who has an idea for using a medicine to treat a newly discovered disease. Design a research study to test if the medicine works. Use either an observational study or experimental (randomized, placebo controlled) study design. Explain why you’ve made these choices for your research design.