Evaluating scientific data
Transcript of Evaluating scientific data
Why be cautious?
• Author’s motivations are not the same as your own– Sell you on a drug,
therapy, hospital, etc– Sell you a magazine– ‘Publish or perish’
• Applies more broadly than health claims Eric
Poehlman
Questions to ask:
1. What is the motivation of the person making the claim?
2. Is evidence based on correlation or causation?
3. What is the inference space?4. How large is the effect?5. How large of a population was tested?6. Is the effect statistically significant?
Correlation or causation?
Correlation • shows a pattern• might suggest a cause• pattern may instead result from unmeasured
3rd variable
How large is the effect?
• ‘Increase’ or ‘Decrease’ alone does not indicate whether it is enough to matter.
• What is measurement without treatment?• How much does measurement change with
treatment?