A COMPUTER-PROGRAM TO PROMOTE UNDERSTANDING OF THE MONITORING METHOD EVALUATION GUIDELINES USED AT NIOSH

A computer-based training program has been devised to promote better u nderstanding of the recently revised National Institute for Occupation al Safely and Health (NIOSH) test guidelines applicable to methods req uiring on-site sample collection and laboratory sample analysis of air borne toxic substances. A statistics section explains the basis of the NIOSH accuracy criterion (NAC); an experiments section provides detai ls on the evaluation experiments; and a calculations section calculate s method statistics based on data entered by the user. The statistics section graphically explains concepts such as the NAT and limit of det ection, allowing the user to experiment with some parameters to see ho w the results are affected. This section also provides background mate rial to show how some of the performance criteria evolved. The experim ents section provides a summary of the experiments used to generate th e data for method evaluation. The calculations section has several scr eens that work like customized spreadsheets for the entry of data coll ected during the laboratory evaluation of a method. A separate screen then calculates the precision (relative standard deviation) of analyti cal results at each of four concentrations, tests to see if the precis ion values are statistically homogeneous, and combines the homogeneous data for calculation of the relative standard deviation, it does the same for bias, and combines the precision with method bias to arrive a t an estimate of method accuracy. Other screens in the calculations se ction facilitate the determination of method limit of detection and sa mple storage stability.