Measurement
Conservativeness
Conservativeness is the principle that, wherever a carbon estimate involves a choice or an unknown, the choice made is the one less likely to overstate the benefit. It is written into most carbon methodologies and into how verifiers read a project.
It applies to every judgement in the chain: which default value to use, where to draw the baseline, how to treat a missing reading, which equation to apply.
A conservative estimate is not a pessimistic one. It is an estimate that will still hold when somebody checks it later with better data.