On the subject in the title: Submitting a sample: the process end to end Working notes rather than a conclusion.
Submitting a sample keeps being re-asked here and I think that is because the answer is conditional and the conditions never travel with it.
Attempting to write the conditional version down properly. Corrections welcome and expected — I would like this to end up as a maintained page rather than a fifth thread.
Building on post #2 rather than restating it.
My understanding of submitting a sample is a few years old and may have been superseded. If it has been, I would genuinely like to know rather than keep repeating it.
Submitting a sample: I would want to see the raw numbers rather than the summary before agreeing. Summaries lose exactly the information that would settle this.
Reading this submitting a sample thread as someone who came in with a fixed view: the third and seventh replies moved me and the confident ones did not.
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.
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.
Noting that the question and the thing people usually mean by it are different.
Careful with the language on submitting a sample. "Not detected" and "not present" are different findings and the first is a statement about the method.
Sensible. I would want the same detail before I acted on it either.
Building on post #11 rather than restating it.
Posting my submitting a sample numbers with the method attached so they can be discounted properly. Uncontrolled, unblinded, and collected by someone who wanted a particular answer.
What I want from this submitting a sample thread is the list of things that would need to be true for the claim to hold. If we can write that list, we can check it.
Post #15 and I disagree about the size of the effect, not about the direction.
Adding a small correction to the submitting a sample summary above rather than a disagreement with it. The substance holds; one of the figures is out by a factor that matters.
Taking post #15 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.
Not a strong opinion, just a consistent one.
I have been on both sides of the submitting a sample argument in this category within eighteen months, which should tell you how strong the evidence for either side is.
Right, and stated more narrowly than I would have dared to state it.
I read post #18 twice before replying, because I had assumed the opposite.
Blind sampling: submitting without the laboratory or seller knowing the source removes the two easiest ways for a result to be shaped: selective submission and selective reporting. The extra effort is worth it.
The short answer was in the first line; everything after is the working.
Everything in post #22 holds. The case it does not cover is the one I have.
Having read the whole submitting a sample thread before replying: the question in the first post has not actually been answered yet, and three of us have answered a nearby one instead.