[Discussion] we are measuring below spec at the wrong time and calling it noise
we are measuring below spec at the wrong time and calling it noise — a position I have arrived at slowly and would like tested.
On inter-lab disagreement, which generates more heat here than anything else.
Two services running different gradients, integrating differently, at possibly different wavelengths, will not produce identical numbers on the same material. A point either way is ordinary. Half a point is close agreement.
The productive response to a gap that size is to post both results with both methods and let the log accumulate. The unproductive response is to pick the lower number, call it the truth, and open a dispute. Members have done the first for long enough now that the bands in the vendor tables are genuinely informative.
Inter-lab variance on this assay runs roughly a point either way, driven mostly by gradient and integration. Two results inside that band agree; they do not disagree quietly.
The template is vendor, compound, batch, service, claim, result, and who paid. Every one of those fields exists because a result missing it has been argued about here before.
Not medical advice, obviously, and nothing here is approved for human use. One person with a spreadsheet.
best — the order this archive was captured in
Date of analysis anchors the result to a manufacturing period. A two-year-old result is evidence about two years ago and should be read that way.
Date of analysis anchors the result to a manufacturing period.
Adding the boring but useful bit: say whether you paid for it. It is the basis of the whole log.
What was the claim on the certificate you are comparing against?
Merged with the other thread on the same batch so the results sit together.
Chain of custody is why member-funded testing is worth more than a supplied certificate: the vial tested is the vial that arrived at a member’s door.
Which service, and did you pay for it yourself?
Cosigning on saying who paid. It is the whole basis on which this log is worth anything.
How many separate lots does your series cover?
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Careful with the trend claim. Four results over two years is a very sparse series to draw a line through.
Area percent or net peptide content?
Do you have the trace, or only the summary?
Fourth lot from the same supplier in the log now and the band has been tight the whole way. That consistency is the actual finding.
inter-lab variance runs a point or two, plan your outrage accordingly
inter-lab variance runs a point or two, plan your outrage accordingly
Disagreeing with this line: that gap is ordinary variance, not a contradiction between the lab and the certificate.
Push back: three tests on one lot is one lot. It tells you about that lot and almost nothing about the next one.
Agreed — the template exists because a result without the batch and the claim is unanchored.
What a result posted here is actually worth, and how to make yours worth more.
A single figure with no batch identifier is about a vial nobody can locate. Add the batch and it becomes about a lot. Add the claimed figure from the certificate and it becomes a comparison. Add the service and the date and it becomes reproducible. Say that you paid for it yourself and it becomes independent.
Five extra fields, thirty seconds of typing, and the difference between a comment and a row in the log that will still be useful in three years.
Kept every report as a PDF with the batch in the filename. Two years in, it is the most useful folder I own.
- 1Date of analysis anchors the result to a manufacturing period. A…11 comments in this branch · started by u/nadia_trevino
- 2Do you have the trace, or only the summary?7 comments in this branch · started by u/noor_vermeulen