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An observational study tracks what happens
In an observational study, researchers can compare people with different habits and can observe associations. This type of study can generate good questions, but it cannot always control all differences between groups.
Randomization adds comparison
In a randomized study, participants are randomly assigned to interventions or comparisons. This helps reduce alternative explanations, although the study must be analyzed further in terms of size, duration, and results.
Why does it matter for DDW?
A statement about treatment or prevention requires stronger evidence than a general observation. When you read about DDW, check whether the result cited comes from the laboratory, observation, or randomized comparison.
The idea to remember
Association is a start. Causality requires a design capable of testing alternative explanations.
Sources and further reading
These references explain the subject and the limits of the evidence. A reference is not proof that a product treats a disease.
Editorial transparency
Published by MECRO SYSTEM SRL. AI tools assist drafting and translation. No named medical reviewer is attributed to this article. This educational material does not replace individual medical advice. Report an error using the contact page, including the article address and the passage concerned.
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