This method is for developing precision statements as reportedin UOP methods and relative bias of the same method betweendifferent laboratories. The calculation of precision, in terms ofrepeatability (within a laboratory), reproducibility (betweenlaboratories) and relative bias (between laboratories) isdescribed. Precision statements in methods having a 98 or latersuffix were developed by the procedure described; methods having an88 through 97 suffix used UOP 888-88, while methods with suffixesearlier than 88 used UOP 666-82.