under coverage
experiment.
random sample.
Correlation ~
Correlation
* * * * *
That is simply not true. Consider the coordinates of a circle. There is obviously a very strong relationship between the x coordinate and the y coordinate. But the correlation is not just small, but 0.
The correlation between two variables is a measure of the linear relationship between them. But there can be non-linear relationships which will not necessarily be reflected by any correlation.
Correlation alone cannot be able to complicate causation.
Asking students eating in the cafeteria if they would like to be part of a study
They are related but one might not be causing the other