How Datum Review assembles and reports data.
Source hierarchy
We prefer, in order: primary datasets we can inspect; published studies stating their sample and method; aggregate industry reports naming their inputs. We avoid figures whose origin is a claim in a marketing page.
What we record for every figure
Origin, sample size, collection period, publication date, and the scope of intent or population the figure covers. These are shown in the methodology block at the foot of each brief.
Our own datasets
Where we publish original data, the methodology is registered before collection begins. We publish inclusion criteria, weights, and the full source list, and we make the underlying dataset available where licensing permits.
Updating
Briefs are living documents. When new data is published on a question we have covered, we revise the brief and date the revision rather than leaving a stale figure in place.