USE OF PREVIOUS EXPERIENCE TO ESTIMATE PRECISION UNCERTAINTY OF SMALL SAMPLE EXPERIMENTS

The determination of precision uncertainty is described for experiments where the test measurements are obtained from single readings or from a limited number of independent readings. For these cases, the limits of precision uncertainty are best determined from previous experience based on larger sample sizes over the full range of variations that occur for a specific test. This paper describes the appropriate procedures to determine the limits of precision uncertainty based on previous experience for small sample experiments. A Monte Carlo simulation technique is used to model the experiments to demonstrate the effectiveness of using the precision uncertainty to determine the range that covers the true test result. Coverages of 95% or greater are found for the techniques investigated.