an assay has a CV of 15% for a standard reference, ie, the same substance tested in the same way in the same lab; all known variables have been controlled and yet there is still a CV of 15%. Supposing the assay variability applies equally to a test substance. Is it possible to estimate the chance of a false positive and a false negative from the variability for the reference and identical variability for the test substance? the reference is used to normalize results across different studies. How should I describe the risk posed by normalization to a reference that is so variable?