One lot is one lot: when a report becomes a pattern — the long version posts 61–90
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
Include the sample handling: how it was stored, how it travelled to the laboratory, how long it sat. A result on badly handled material is measuring the handling.
Old habit: I write down the expected answer before I calculate it.
Do not adjust a reported figure. Post what the laboratory said and put your interpretation in a separate sentence.
Filing this under things that are true until someone shows me otherwise.
The arithmetic in post #63 is right; the assumption feeding it is the part to check.
Reports of ordinary results are more valuable than reports of remarkable ones, precisely because only the remarkable ones get posted elsewhere.
Multiple services on one lot: agreement across two independent laboratories is stronger than a high number from one. Our vendor pages deliberately mix services for that reason.
Flagging that the sources on this are thinner than the confidence in the thread suggests.
Where you submitted more than one vial from a consignment, say so. Intra-consignment comparison is one of the more useful things an individual can contribute.
The number is defensible. The precision I gave it is not.
Post #63 describes the usual case. This is about the unusual one.
Recording a reorder result against the original is one of the highest-value contributions here, because consistency over time is what a single result cannot show.
Adding the measurement that post #67 says would settle it.
The cost of a submission is worth stating. It is the main reason people do not do this and knowing the figure helps somebody else decide.
This follows post #67 rather than contradicting it.
The cost of a submission is worth stating. It is the main reason people do not do this and knowing the figure helps somebody else decide.
Two people can read the same figure differently here and both be reasonable.
Useful. I had the fact and not the reason, which turns out to be the important half.
Where you have no independent result, a documentation report is still worth filing: what the certificate contained, what it omitted, and how fast a request was answered.
It is worth checking rather than assuming, which costs nothing.
Picking up post #74: that is the part I would want checked first.
Structured report format: compound, lot, independent testing service, method as reported, result, and the certificate figure for the same lot. One lot is one lot. It becomes a pattern at three or four, and it becomes a disputed record when asked and not explained.
Collapsed as off-topic by two members at trust level 3 or above
On post #72 — agreed on the reasoning, with one qualification.
Lot matching: confirm the lot number on the certificate matches the lot number on the vial. A result from a different lot is not evidence about your vial.
Adding a source would improve this post and I do not have one to hand.
Recording a reorder result against the original is one of the highest-value contributions here, because consistency over time is what a single result cannot show.
Somebody will have a better source than mine, and I hope they post it.
Do not adjust a reported figure. Post what the laboratory said and put your interpretation in a separate sentence.
Date the report: when the analysis was done matters. Material can degrade in storage. A report from two years ago is still useful but is not evidence about the current state of the same supplier's stock.
That is a description of practice, not a recommendation of it.
The maintainers will ask for missing fields rather than rejecting a report. Filling them in afterwards is normal and nobody minds.
Adding this to the thread rather than to the wiki, because I am not confident enough for the wiki.
Do not adjust a reported figure. Post what the laboratory said and put your interpretation in a separate sentence.
Reports of ordinary results are more valuable than reports of remarkable ones, precisely because only the remarkable ones get posted elsewhere.
I had written a reply contradicting post #81 and deleted it. Here is what survived.
One lot is one lot. It becomes a pattern at three or four, and the record is built to show which of those you are looking at.
A partial answer, offered because a partial answer beats none.
Confirming post #81 from a second method, which matters more than confirming it from a second person.
Photograph the vial and the label before opening. It costs ten seconds and it is what turns a report into something checkable.
I would want to see it done twice before believing it once.
Date the submission as well as the result. Turnaround is part of what people want to know and it disappears if only one date is recorded.
That is what the documentation says. What happens in practice is usually close.
Where I part company with post #85, and it is a narrow parting.
The format we ask for is compound, lot, testing service, method as reported, result, and the certificate figure for the same lot. A report missing any of those goes to the discussion rather than the record.
This is the sort of thing that ought to be settled and apparently is not.
Post #85 and I disagree about the size of the effect, not about the direction.
Where you have no independent result, a documentation report is still worth filing: what the certificate contained, what it omitted, and how fast a request was answered.
Two sources, same conclusion, and I could not rule out that one copied the other.