Another question has gotten me thinking about testing more than just correlated/not correlated. Let's say that I have some data and find the correlation to be $0.15$. However, I then realize that correlation doesn't really interest me unless it's at least $0.10$. Moreover, a correlation of $-0.10$ is equally interesting, and I don't care about the sign, just if the variables have a sufficiently strong relationship for me to care.
I have gotten as far as thinking that I would want to test my observed $r^2$ against a null of $\rho^2\le 0.1^2 = 0.01$. I cannot think of a good way to test this. Certainly if I want to test against $\rho^2=0$ then I can just do a permutation test.
What about if I want to test the more general $\rho^2\le \eta?$
Thanks!