Second pass at: The mass-error checker and its intended scope

Two sentences on mass-error checker and then I will stop, because the rest is speculation and the thread is better without mine.

What is documented is narrow. What is inferred from it is broad. The gap between them is where every argument here lives.

Worth separating two things that post #9 runs together.

A saved calculation is worth more than a remembered one. Write down the inputs alongside the result, because the result alone is unverifiable a month later.

Adding it in case it saves somebody the afternoon it cost me.

Unit-conversion tools are only as good as the assumption they make about the syringe. Ask what barrel and what graduation interval it assumed before trusting the units figure.

I have separated what I observed from what I concluded, which does not always happen.

Where I part company with post #24, and it is a narrow parting.

The honest answer on mass-error checker is that it depends, and the useful part is the list of what it depends on. Four items, in rough order of how much they matter.

Most people get the first two right and then argue about the fourth.

What I would tell a new member reading about mass-error checker for the first time: the confident posts are not the reliable ones, and the reliable ones are longer.

On mass-error checker, I would rather understate and be corrected upward than overstate and be quoted. That is a house style here and it is a good one.

Practical experience of mass-error checker, offered as one case with the conditions stated, not as a general finding. Conditions first, because they are what make it interpretable.

The reason mass-error checker 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.