PeptideMeter (revision 2)

PeptideMeter is a public database that collects submitted peptide test results and aggregates them into tallies by supplier and by compound, with individual entries traceable to the report they came from. It is one of the four testing and review services referred to throughout this wiki.^[1]

A database of this kind produces a different kind of object from an analytical laboratory. Janoshik Analytical and Medutest produce determinations on samples; PeptideMeter produces statistics over submissions. Treating an aggregate figure as though it were a measurement, or a measurement as though it were representative, are the two errors this distinction is meant to prevent.^[1]

An aggregate over submissions is a statistic about the submissions, not about the supplier's output. If ten reports on a supplier's material show a mean purity of 98.6%, that is a fact about ten samples that somebody chose to test and chose to submit.^[1]

The spread matters more than the mean. A supplier with ten submissions clustered within half a percentage point is characterised differently from one with ten submissions spanning five points at the same mean, and a bare mean conceals the difference. Where a distribution is available it is more informative than any single number derived from it, since the attributes a peptide specification covers are themselves multiple.^[2]