The Use of the Angular Transformation in Biological Assays

Abstract

For biological assays designed to compare a sample of unknown potency with a standard in terms of % response, the angular transformation is advocated as giving essentially the same results as the probit transformation but requiring much less computation. Several modifications of assay design permit further simplification. By using the same number of animals for each dose, only 2 dosage levels each of standard and unknown, and a constant ratio of high dose to low dose, results may be so simplified that a graph and nomograph suffice for computing potency and estimated standard error of assay.