Explanation: ARI collected two samples from the same person at the same time, and sent both samples to the lab for testing (without the lab’s knowledge). This was done for at least 2 people for every test (four or more total samples). The results from the lab were then analyzed to determine how closely they were able to reproduce the same results for the same person. To receive a Pass, we required no more than 10% of the tests had a minor error (differ by 30-50% of the reference range) and no more than 10% of the tests had a major error (differ by 50% or more). We use the reference range instead of the absolute value because some tests have very narrow reference ranges, so it is important to interpret differences in terms of the reference range.