Effects of scientific advances on the decision-making process: analytical chemistry

The analytical chemist has taken the science of identification and quantitation of chemical compounds far beyond the capability of the toxicologist to correlate with the results of animal experiments. In pursuing the vanishing zero, however, the analytical chemist has failed to acknowledge the inherent variability of chemical measurements at very low concentrations that manifest itself not only as discrepant values but as an appreciable fraction of false positive and false negative results and as real negative values (the blank or control is greater than the determination). These are the symptoms of a system not in statistical control. The same type of variable results, evident in biological systems as "biological variability," are then manipulated by statisticians as if they were reproducible measurements. Progress in characterizing biological uncertainty cannot be made until the invisible systematic error of individual laboratories is transformed into random error, amenable to the application of statistical principles. In measurement theory, an examination and correction of systematic error requires knowledge or assignment of a "true value," a concept that does not appear to exist in many biological systems.