Observational vs Experimental Studies Statistics Example 4
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Example 4
hardExplain why some research questions can only be studied observationally, not experimentally. Give two examples and discuss the ethical or practical reasons.
Solution
- 1 Step 1: Example 1: Effect of smoking on lung cancer — it would be unethical to randomly assign people to smoke. Researchers must rely on observational data comparing smokers and non-smokers. Example 2: Effect of earthquakes on mental health — we cannot cause earthquakes, so we must observe communities before and after natural disasters.
- 2 Step 2: Ethical constraints prevent imposing harmful treatments (smoking, poverty, violence). Practical constraints prevent controlling natural events (weather, genetics, historical events). In these cases, well-designed observational studies with large samples and statistical controls for confounders provide the best available evidence.
Answer
Examples: (1) smoking and cancer (unethical to assign smoking), (2) earthquakes and mental health (impractical to cause). Ethical and practical constraints limit experiments; observational studies with careful controls are the alternative.
Not all research questions can be studied experimentally. When ethical or practical barriers prevent random assignment of treatments, observational studies are the only option. These studies require careful design to minimise confounding, using techniques like matching, statistical adjustment, and large sample sizes.
About Observational vs Experimental Studies
Observational studies gather data by watching subjects in their natural setting without any intervention, while experimental studies deliberately assign treatments to subjects and measure the outcomes. Only experiments, through random assignment, can establish cause-and-effect relationships.
Learn more about Observational vs Experimental Studies →More Observational vs Experimental Studies Examples
Example 1 easy
Classify each study as observational or experimental: (a) Researchers track the diets of 1000 people
Example 2 mediumA study finds that people who drink green tea have lower rates of heart disease. The study surveyed
Example 3 mediumA school wants to know if a new teaching method improves maths scores. Method 1: compare scores of s