Trust the process

Methodology

OurBlueDot treats methodology as part of the product, not a footnote. Layer pages describe the indicator, transformation, period, unit, coverage, and known limitations.

Dataset selection

The observatory prefers source quality, methodological transparency, licensing, long-term maintainability, and user value over maximizing country counts. Coverage of UN member states is recorded honestly; it is not the deciding reason to choose or reject a dataset. A layer may cover far fewer than 193 countries when the source is authoritative, the metric is meaningful, the method is clear, and the license allows reuse.

Comparable values

We rank or compare only values sharing a compatible definition and period. Missing data remains missing; it is never silently converted to zero, interpolated, or synthesized to fill the map. Grey countries are an intended outcome, not a defect. When a layer is explicitly derived, estimated values are allowed only with a published rule and a per-value reported or estimated label.

Calculated layers

Calculated layers, such as day length, state the formula and representative location used. They are mathematical estimates rather than observed measurements.

Modelled layers

Modelled layers, such as PM2.5 exposure, temperature change, Employment Rate, and Adult Obesity Rate, republish source-modelled estimates rather than station readings, labour-force survey microdata, or an air-quality index. Adult Obesity Rate is the first Health layer imported directly from the WHO Global Health Observatory rather than World Bank WDI. Missing countries remain missing; modelled gaps are not filled with zero.

Derived layers

Derived layers, such as Estimated Literacy Rate, combine published source series under an auditable hierarchy. Users can see whether a country value is a reported UNESCO/WDI literacy figure or an OurBlueDot estimate. Estimates are never presented as official surveys.

Demonstration data

Demo layers are clearly labelled and excluded from search-engine indexing. They validate the interface and data model, not factual claims.

Updates and corrections

Each source records its expected update cadence. Material methodology changes should be reflected in the layer description and source notes.