Blind submission and why it changes minds — the long version posts 31–60
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
Narrowing post #30, 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.
Caveat: everything above assumes the paperwork is what it says it is.
Collapsed as off-topic by two members at trust level 3 or above
I have no financial interest in anything named in this thread and I want to say so before I comment on Blind submission, because it is the sort of subject where it matters.
A methods point on Blind submission rather than a substantive one: if the comparison is not like for like, the difference you are measuring is the difference in method.
Answering the question post #32 raises rather than the one it answers.
Medutest: combined purity and identity reporting. Appears throughout vendor documentation. Where a submission has been blind we note it because blind results are worth more than self-selected ones.
Flagging that the sources on this are thinner than the confidence in the thread suggests.
Adding a reference point for Blind submission. Mine is a single case, collected without controls, and I am posting the method alongside it so it can be discounted appropriately.
The failure mode on Blind submission is boring rather than dramatic. It is almost always the step everyone assumes was done correctly because it is too simple to get wrong.
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.
Genuinely open to being wrong about this one.
Summarising the Blind submission thread so far, since it is long and the answer is buried: the first reply has the method, the fourth has the correction to it, and the rest is people agreeing at length.
Building on post #39 rather than restating it.
Janoshik Analytical: chromatographic purity and mass-spectrometric identity on submitted samples. Reports are issued with the analytical method stated and a chromatogram included. Submission is by mail.
Post #38 put the caveat in the right place and I want to underline it.
The reason Blind submission keeps being re-asked is that the answer is conditional and people quote it without the condition. It is not that the answer is unknown.
Seconded. It reads as careful rather than confident, which is the right register.
What I would want before treating Blind submission as settled: the method, the sample, and whether anyone tried to find the opposite result. Two of the three are usually missing.
Post #44 is the version of this I will quote in future. One addition.
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.
Medutest: combined purity and identity reporting. Appears throughout vendor documentation. Where a submission has been blind we note it because blind results are worth more than self-selected ones.
The confident version of this sentence would be wrong, so here is the hedged one.
Taking Blind submission seriously for a moment rather than deflecting: the honest position is that the community has observations and no controlled comparison, and those two things support very different sentences.
Answering the question post #46 raises rather than the one it answers.
Marking my uncertainty on Blind submission explicitly. I am confident about the direction, much less confident about the size, and not confident at all that it generalises past the case in the first post.
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 holds under the stated conditions and I have stated them.
Understood. Thank you for being specific about the limits of it.
What I would tell a new member reading about Blind submission for the first time: the confident posts are not the reliable ones, and the reliable ones are longer.
Picking up post #53: 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.
I would hold that lightly until someone with a larger sample weighs in.
An update on my earlier Blind submission post: the pattern held for another six weeks and then stopped, which I did not predict and cannot explain.
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 to see it done twice before believing it once.
Post #53 describes the usual case. This is about the unusual one.
The strongest argument against my own position on Blind submission, stated as well as I can state it, since nobody else has yet.
The record shows what was measured. Everything beyond that is inference and this site tries to keep the line visible.
Adding it in case it saves somebody the afternoon it cost me.
Noted, and thank you for writing it out rather than summarising it.