The Validity and Meaning of the Results of Biological Assays
N. K. Jerne, Eric C. Wood · Biometrics · 1949
IN MAY 1948, one of us (N. K. J.) wrote to Mr. D. J. Finney making certain comments on his paper [13] on the adjustment of biological assay results for variation in concomitant observations. Mr. Finney, after replying to this letter, discussed the points raised with the other of us (E. C. W.), and a tripartite correspondence ensued in the course of which almost every link in the long chain of reasoning and inference from the performance of a biological assay to the statement of its results was critically examined. It seemed to us, whose own thinking on the subject had been much clarified, that the main conclusions at which we had arrived might usefully be brought together and placed on record for the benefit of those who might not have had occasion to give so much thought to the theoretical background of biological assays. This background is surprisingly complex and varied. Behind the experimental design of an assay, and still more behind the final statement about the result and its fiducial limits, there lies a whole host of assumptions and implications. Some are chemical or biochemical, about the nature of the Test Preparation (T.P.) whose potency is to be assayed and that of the Standard Preparation (S.P.) with which it is to be compared. Some are biological or pharmacological, about the response evoked in the experimental animals by the stimulus of the doses administered to them. Some are mathematical and in particular statistical, about the computational processes by means of which the numerical results are evaluated. Some, even, are philosophical-if not metaphysical!-about the relations between the theoretical abstractions of