Answer:
The third-variable rule
Explanation:
We will have a better understanding of the third-varibale rule or problem, when we understand correlation.
We can definition correlation as being always low on internal validity.
It is the possibility that some extraneous variable is responsible for the correlation that was found between the two variables of interest this is because it caused both of them.
It can take its extreme form.
Here, the third variable can be said to be the entire cause of the correlation between the two variables of interest and there's no causal relationship between them at all. This would make the correlation between the two variables of interest spurious.
