Thread: Spearman Rank value validity

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

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.
-Andy

could you be more specific, how many values make it valid? also i have done the calculation and the result was a 90% correlation or thereabouts