Your sample size is not large enough, thus you would not get a low enough p-value to prove any statistical significance to your claim. Increase your sample size if you can.
I am using spearman rank to test the strength of the correlation between gradient and velocity along a river. i measured on 8 sites but my teacher says i need more sites for it to be mathematically correct.
is this true?
if not could you please provide a link to some proof or my coursework will be invalid.
Thank you very much for reading