ABSTRACT
Prior to the publication of Realistic Evaluation of the Precision and Accuracy of Instrument Calibration Systems by Churchill Eisenhart, the terms "precision" and "accuracy" were used in a qualitative manner to characterize measurements. These terms appeared in many American Society for Testing Materials (ASTM) standards long before any common agreement or understanding had been reached as to their meanings and consequences. Three basic concepts in the paper were immediately accepted by metrologists at National Bureau of Standards (NBS), namely: a measurement process requires statistical control; statistical control implies control of both reproducibility and repeatability; and a measurement result requires an associated statement of uncertainty that includes any possible source of bias. Churchill Eisenhart was brought to NBS from the University of Wisconsin in 1946 by Edward Condon, Director of NBS, to establish a statistical consulting group to "substitute sound mathematical analysis for costly experimentation."
