Significance and Use This test method is considered satisfactory
for use as a referee method for the determination of the wool
base content and the clean wool fiber present in a lot of raw
wool. If there are differences of practical significance between
reported test results for two laboratories (or more),
comparative test should be performed to determine if there is a
statistical bias between them, using competent statistical
assistance. As a minimum, use the samples for such a comparative
test that are as homogenous as possible, drawn from the same lot
of material as the samples that resulted in the disparate
results during the initial testing and randomly assigned in
equal numbers to each laboratory. The test results from the
laboratories involved should be compared using a statistical
test for unpaired data, probability level chosen prior to the
testing series. If bias is found, either its cause must be found
and corrected, or future results for that material be adjusted
in consideration of the known bias