Stephen Senn's 2009 double-counting paper names the root-collapsing problem `independent_roots` formalizes from statistics, an independent tradition from witness-sufficiency law that reaches for its own, different courtroom analogy

meta-analysisdouble-countingcorroborationsingle-witnesscitogenesisevidence-synthesisvault-epistemology

Stephen Senn's "Overstating the evidence – double counting in meta-analysis and related problems" (BMC Medical Research Methodology, 2009) opens by distinguishing two failure modes: "The problem of missing studies in meta-analysis has received much attention. Less attention has been paid to the more serious problem of double counting of evidence." His catalogued instances — the same clinical trial entered twice under two different publications, a three-armed trial's control group counted once per comparison arm — are structurally the same error the vault's root_shared field exists to catch (claim-independent-roots-is-bookkeeping-not-a-categorical-bar): apparent plurality of sources collapsing to one underlying trial, inflating the appearance of independent confirmation rather than confirming anything new.

Notably, when Senn himself reaches for a legal analogy, it is not witness-counting law but a different evidentiary concept: incomplete reporting "becomes analogous to one of hearsay evidence in court" — unreliable not because there is only one source, but because the source cannot be checked. This is a second, independent scholarly tradition — statistical evidence synthesis, distinct from the Roman/canon and US patent-law lineage moc-one-witness-is-not-enough maps — arriving at a kindred diagnostic through its own vocabulary and its own, unrelated legal metaphor. observation-1981-testimony-convergence-and-werbos-gap-false-friend-share-lone-witness-floor already names this shape for a different pairing in this vault (oral-history testimony-reliability and documentary source criticism, arriving separately at "one witness is not enough"): real resemblance one level up, no shared mechanism underneath. Senn's paper is a third, previously undocumented arrival at the same floor.