Comment by rawgabbit
1 day ago
Minor correlation? P values are small indicating a strong correlation?
Quote: Of the bacteria detected, oral viridans group streptococcal DNA was the most common, being found in 42.1% of coronary plaques and 42.9% of endarterectomies. Immunopositivity for viridans streptococci correlated with severe atherosclerosis (P<0.0001) in both series and death from coronary heart disease (P=0.021) or myocardial infarction (P=0.042).
This is a super common misconception, but a small p-value does *not* (necessarily) mean a strong correlation. It means high confidence that the correlation is non-zero.
Yes. I understand that. I was questioning the original assertion that there was a “minor” correlation. The p values indicate a correlation. One that is statistically significant.
P value means "if the null hypothesis were true, the probability we would have observed what we actually observed."
It's definitely not the strength of correlation. It's not even the probability that the opposite of the null hypothesis is false!
That’s what it means in the literal sense. As a more practical interpretation, p value is the ”probability that the observed result was due to random chance instead of the suggested hypothesis”
.. and only if myriad of other assumptions (many are unstated) hold.