Easily verified by testing more. (Via law of big numbers.) Unless the test is biased which means we're back to square one - discerning bias of the test from bi

Easily verified by testing more. (Via law of big numbers.) Unless the test is biased which means we're back to square one - discerning bias of the test from bias of respondent. To do that you'd have to produce a specifically biased test in a different way, see how the noises add.