Principles
- Every figure has a source. Each number on the site names its publisher, the dataset version it came from, the date it was published here, and its licence.
- We do not make up or estimate figures. If a source has not published a number, we show that it is missing rather than fill the gap.
- A person approves everything. Imports are automatic, but nothing reaches the public site until a reviewer has checked it and the source's licence has been approved.
- Nothing is overwritten. New data arrives as a new version. Earlier versions are kept, so a figure cited last year can still be traced.
- We show our working. The original file from every import is stored unchanged with a checksum, and every review, publication and correction is recorded in an audit log.
How a figure gets here
- Source registered. We record who publishes the data, what it covers, how often it is updated, and its licence. A steward reads the licence and approves or rejects it.
- Data collected. For publishers with a data service, such as the World Bank and the DHS Program, a connector downloads the figures on a schedule. For publishers that only release reports and spreadsheets, such as the National Bureau of Statistics, our data team uploads the file.
- Original kept. The downloaded or uploaded file is stored exactly as received, with a SHA-256 checksum, before anything is changed.
- Checked automatically. Each figure is matched to a registered indicator, place and period. Checks flag values that are missing, not numeric, duplicated, out of range, or very different from the previous version.
- Reviewed. A reviewer looks at the checks and the contents and approves the version, asks for changes, or rejects it. Blocking problems must be resolved first, and in normal use the person who imported a version cannot approve it.
- Published. A publisher makes the approved version live. It replaces the previous version on the site, in downloads and in the API, and the previous version is kept.
The full list of sources, their licences and every published version is on the sources page.
Versions and citing
Each figure belongs to a dataset version, for example "World Bank WDI, version 2". The version and its publication date appear under every chart. Indicator pages have a ready-made citation and links to download the series as CSV or JSON.
Figures published by international organisations sometimes differ from national figures, because of different methods, definitions or revision dates. Where we publish both, they are kept as separate indicators and each is labelled with its publisher.
Elections
Our election pages report the official timetable, candidates and results as published by the Independent National Electoral Commission (INEC). We do not endorse parties or candidates, and we do not publish polls or predictions.
Problems and corrections
If you think a figure is wrong, use Report a problem, or the link under any chart. We check every report against the original source. When a published figure was wrong, we publish a corrected version and record what changed on the corrections page.