Sources & methodology

A useful atlas should tell you where its numbers come from, what they mean, and where caution is needed. This is the current record of how WorldSumma handles its data.

Country indicators

Population, surface area, nominal GDP, and nominal GDP per capita come from the public World Bank API. WorldSumma stores the most recent non-empty observation available for each country and indicator.

Population: SP.POP.TOTL
Surface area (km²): AG.SRF.TOTL.K2
GDP, current US$: NY.GDP.MKTP.CD
GDP per capita, current US$: NY.GDP.PCAP.CD

Open World Bank Data

Places, maps, and identifiers

Country, division, and city records live in WorldSumma’s maintained atlas database. Reference fields can have different upstream histories; a single field-level source ledger is not yet available for every record, and we do not pretend otherwise.

Maps: OpenStreetMap attribution with CARTO-rendered base tiles.
Place identifiers: Wikidata IDs are shown where present.
Coordinates: point locations describe a reference position, not a legal boundary.
Capitals: the current place record has one principal capital field and may not express every country’s split-capital arrangement.
Classifications: countries, territories, and administrative types follow the stored dataset and can reflect contested conventions.

How rankings work

Latest available, not one shared year.

Rankings exclude rows with no value for the selected metric, then order the remaining countries and territories. Because the World Bank’s latest observation can differ by country, a ranking may combine reporting years. Economic tables show the stored year where available.

Nominal GDP measures the size of an economy in current US dollars. GDP per capita is that total divided by population. Neither measure describes wealth distribution, household income, purchasing power, wellbeing, or quality of life on its own.

Surface area is not the same as land area. Rankings use the World Bank surface-area indicator and label it accordingly.

AI-assisted narrative disclosure

Some country, division, and city overview prose is generated with a language model. The generation workflow supplies structured atlas facts and, when available, a Wikipedia summary as reference material. The model is told not to invent uncertain figures and to rewrite rather than copy.

This prose is contextual reading, not a primary source. Structured facts and linked sources should take precedence if there is a conflict.

Corrections and responsible use

Geographic names, boundaries, population estimates, and economic observations change. Verify high-stakes decisions against the linked primary source and relevant official authority.

Report a data issue

This methodology page reflects the current repository implementation. As field-level provenance and review timestamps improve, this page should become more specific—not more vague. Return to the About page to read the product principles behind that approach.