Choosing which test to pay for, given a fixed budget posts 31–60
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want.
On balance I think that is right, and I would not bet much on it.
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.
Picking up post #33: that is the part I would want checked first.
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.
Small point, but it is the one that usually catches people.
Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want.
Worth separating two things that post #33 runs together.
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.
Two people can read the same figure differently here and both be reasonable.
Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want.
Narrowing post #42, because the general version has more than one answer.
A record with four results over sixteen months is a thin record rather than a bad one, and the honest description says which.
I would want the raw data before agreeing with my own summary of it.
Everything in post #40 holds. The case it does not cover is the one I have.
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 saying I have only my own numbers here, and n is small.
Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want.
Take it as a starting point and not as a specification.
The record shows what was measured. Everything beyond that is inference and this site tries to keep the line visible.
Sensible. I would want the same detail before I acted on it either.
I read post #44 twice before replying, because I had assumed the opposite.
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.
Someone should write this up properly, and it should probably not be me.
Picking up post #46: that is the part I would want checked first.
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.
I am describing what is, rather than arguing for what should be.
Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want.
The arithmetic in post #52 is right; the assumption feeding it is the part to check.
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.
Written from notes rather than memory, which is why the numbers are specific.
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.
On reflection I would soften that slightly.
Everything in post #55 holds. The case it does not cover is the one I have.
Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want.
It is the sort of thing that seems obvious in retrospect and was not at the time.
Narrowing post #55, because the general version has more than one answer.
The record shows what was measured. Everything beyond that is inference and this site tries to keep the line visible.
The evidence for this is thinner than the way I have phrased it suggests.
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.
Not disagreeing with anyone above, just adding the bit I keep having to look up.
Taking post #59 at face value and following it one step further.
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 worth stating the boring hypothesis before the interesting one.