Choosing which test to pay for, given a fixed budget — does this still hold? posts 31–40

Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want.

Cross-checking one lot with two services independently is the cleanest test available and is rarely done because it costs twice as much.

It does not extend to lots nobody has seen, it is not a recommendation, and it says nothing about anything other than what was measured.

Worth one more sentence than it usually gets.

Coming back to post #30, because the follow-up matters more than the original answer.

A record with four results over sixteen months is a thin record rather than a bad one, and the honest description says which.

The interesting part of this is the exception, and I do not understand the exception.

Reading rather than answering, but this is the post I would point somebody at.

The record shows what was measured. Everything beyond that is inference and this site tries to keep the line visible.

Not the answer, but possibly the question that gets there.

I had written a reply contradicting post #34 and deleted it. Here is what survived.

Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want.

That is a description of practice, not a recommendation of it.

Repeat testing: if you want to verify the same lot a second time, testing with a different service strengthens the conclusion. Testing with the same service verifies reproducibility but uses the same method.

The evidence for this is thinner than the way I have phrased it suggests.

Answering the question post #38 raises rather than the one it answers.

It does not extend to lots nobody has seen, it is not a recommendation, and it says nothing about anything other than what was measured.

It is the sort of thing that seems obvious in retrospect and was not at the time.