Saved cohorts · versioned
membership never changes silently| Cohort | Definition | Included | State |
|---|---|---|---|
| COH-BST-WW-v4 | biological seed treatment vs untreated · winter wheat · weighbridge basis | 23 | 17 candidates awaiting review |
| COH-NUE-2526 | nitrogen-use efficiency · stratified by soil series | 19 | 3 method incompatibilities flagged |
| COH-COVER-SB-v2 | overwinter cover vs stubble · spring barley · VESS + yield | 11 | current |
| COH-RN-META | reduced-N systems · yield held vs standard | 31 | current |
| COH-SOM-LOI | soil organic matter · LOI method only | 4 | below k=5 — aggregates withheld |
| COH-MT-TRANS | min-till transition years 1–3 · yield + fuel | 14 | current |
COH-BST-WW-v4 · membership
Definition (canonical filters, exposed): crop = winter wheat · practice = biological seed treatment · reference arm present · metric = yield · unit = t/ha · basis = whole field · method = weighbridge (v4: + calibrated yield monitor) · seasons 2024–25
23
strictly compatible · poolable
105
excluded · every reason named
+0.2
median difference t/ha · n=23 · opens to sources
| Record | Difference | Standing | Included? | Reason |
|---|---|---|---|---|
| PRF-UK-H-000554 | +0.4 t/ha | corroborated | included | all criteria met |
| PRF-UK-A-000231 | +0.2 t/ha | protocol locked | included | all criteria met |
| PRF-UK-D-002204 | −0.05 (null) | evidence reviewed | included | null results included by design |
| PRF-UK-F-001873 | −0.3 t/ha | protocol locked | excluded | reference arm includes fungicide — different question |
| PRF-UK-K-000412 | −0.2 t/ha | structured | excluded | plot-combine basis — not poolable with weighbridge |
| PRF-FR-K-000966 | pending | structured | candidate | outcome not yet measured · method alignment under review |
19 further included and 101 further excluded records · adverse and null results carry the same weight in membership as favourable ones.
Provenance graph · how the evidence connects
structure, not just totalsCohort diff · v3 → v4
what changed, exactly| Change | Records | Why |
|---|---|---|
| + admitted | 6 | amendment 14 Feb 2025: calibrated yield monitors accepted |
| − removed | 2 | addendum on PRF-UK-A-000188 changed N context — no longer same-management |
| ± value changed | 1 | corrected rate propagated · median unchanged |
v3 remains frozen and reproducible; every export cites the version it used. New outcomes and addenda re-run the diff, never silently change the result.
Snapshots
| Snapshot | Cohort | Frozen |
|---|---|---|
| SNAP-2026-06-30 | COH-BST-WW-v3 | 30 Jun 2026 · cited twice |
Cohort rules: saved, versioned, snapshot-able; strictly-compatible vs related-context is explicit; every inclusion
and exclusion carries its reason; aggregates only over poolable records with k=5 fail-closed; every number opens to sources.