Sources & data policy
Every major claim and every chart names a source type. We do not assign a single reliability score to a source.
Reuse
Published data is free to reuse under CC BY 4.0 unless a dataset says otherwise. Cite the dataset ID and version. Charts stay pinned to the version they were drawn from - they do not silently rewrite when a later correction lands.
Source types we name
- Official statistics
- Published statistical yearbooks, census volumes and ministry tables. Preferred for long-run national series when definitions can be stated.
- Administrative records
- Programme and agency returns. Useful for coverage; often need a note on who is counted.
- Peer-reviewed study
- Used when a finding rests on academic measurement, with the paper cited by title and year.
- Survey
- Named instrument and wave. Definitions of the question matter as much as the rate.
- Media report
- Allowed for dated events and announcements; never as the sole source of a quantitative series.
- ContextLens derived
- A figure we calculated from other sources. The derivation sits with the dataset version and is citable.
Missing data
Missing observations are gaps, never zeros. Provisional values are labelled. Pre- and post-break series that use different sources say so on the page.
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