The DFO stores every source it ingests in one knowledge graph, served by a Data Commons instance. Each node in the graph has an identifier, its dcid. Each number is an observation of a statistical variable (a StatVar) about one or more entities, and every component, from a country to a purpose code, is a node. Every source follows the same steps with its own columns. This page follows one record from the OECD's Creditor Reporting System (CRS), which records each aid activity donors report.

One CRS record

France reported basic health care grants to Togo in 2008. The DFO's CRS pipeline reads these columns for that year.

In the terms of the OECD's Development Assistance Committee (DAC), the record shows donor France, recipient Togo, flow type ODA, finance type 110 (standard grant), modality C01 (project-type intervention), purpose 12220 (basic health care), and 3.97 million US dollars disbursed. Where the numbers come from explains how the DFO sums records and scales amounts before they reach the graph.

What each column becomes

The donor and recipient codes are looked up in the ontology's code table. Code 4 is country/FRA and code 283 is country/TGO. Those are the Data Commons country nodes, so a DFO observation about Togo sits on the same node as every other dataset about Togo.

The other four coded columns become classification values. Each value is a node with a label and description. Its property, such as crsPurpose or crsTypeOfFinance, is a node too. A lookup for CRSPurposeCode12220 returns a node in this form.

{
  "ref": "CRSPurposeCode12220",
  "kind": "code",
  "label": "basic health care (CRS Purpose)",
  "types": [
    "CRSPurposeCodeEnum"
  ]
}

DFO_API=https://developmentfinance.org
curl -s "$DFO_API/api/v1/graph/node/CRSPurposeCode12220" | jq '{ref, kind, label, types}'

Each amount column becomes a different StatVar:

• usd_disbursement is a FinancialFlow with financialFlowType Disbursement and nettingBasis Gross, measured as an amount.
• usd_disbursement minus usd_received is the same flow with nettingBasis Net.
• usd_commitment is a FinancialObligation with financialObligationType Commitment, measured as an amount.
• usd_grant_equiv is a FinancialFlow with financialFlowType Disbursement, measured as a grantEquivalent.

The StatVar

A StatVar names one kind of number precisely enough that two observations of it can be compared. The pipeline builds its dcid from the measure and every classification value in a fixed order.

Amount_FinancialFlow_Gross_Disbursement_CRSTypeOfFlow10_CRSTypeOfFinance110_CRSCooperationModalityC01_CRSPurposeCode12220_Nominal

The graph returns this StatVar.

{
  "ref": "Amount_FinancialFlow_Gross_Disbursement_CRSTypeOfFlow10_CRSTypeOfFinance110_CRSCooperationModalityC01_CRSPurposeCode12220_Nominal",
  "label": "Official development assistance gross disbursements for basic health care (standard grant, project-type intervention)",
  "roles": [
    "financingProvider",
    "financingRecipient"
  ],
  "population_type": "FinancialFlow"
}

curl -s "$DFO_API/api/v1/graph/node/Amount_FinancialFlow_Gross_Disbursement_CRSTypeOfFlow10_CRSTypeOfFinance110_CRSCooperationModalityC01_CRSPurposeCode12220_Nominal" |
  jq '{ref, label, roles: .stat_var.definition.roles, population_type: .stat_var.definition.population_type.ref}'

The observation supplies the donor, recipient, and year, and the StatVar carries the modality. So a question that leaves modality open, such as "ODA standard grants for basic health care from France to Togo", matches several StatVars: one for each modality France used, plus one for records with no modality.

The observation

An observation is one number: a StatVar, its entities in their roles, a date, a value, and a unit. The 2008 observation appears in a download as this row, shown here without its label and conversion columns.

Nominal at the end of the StatVar dcid means current prices, the way the CRS reports them. Methods explains how a request converts amounts to another currency or to constant prices.

Roles

A role is the position an entity holds on an observation. Each StatVar declares its roles in its observationProperties, and a download has one column per role. The CRS StatVars declare two, financingProvider and financingRecipient. In the World Bank's International Debt Statistics (IDS), a country's total external debt declares only financingRecipient, and the same total by creditor adds financingProvider. A StatVar that declares no roles, such as a country's gross national income in the IDS, uses the Data Commons default, observationAbout.

A dataset spec names the same entities by flow axis, with the provider as origin and the recipient as destination. Versions and snapshots shows a spec.

Facets

The same number can exist in more than one edition, reported by a different source, in a different unit, or measured by a different method. Each edition is a facet. A facet has three axes: provenance, unit, and measurementMethod. The 2008 row above has one facet, provenance provenance/OECDCreditorReportingSystem in CurrencyUSD.

A provenance node records who published the data and on what terms. The CRS provenance node names the OECD (dc/s/OrganisationForEconomicCo-operationAndDevelopmentOecd) as publisher, the OECD terms and conditions as its licence, and the date of its last refresh. Where two facets cover the same observation, the Datasets API picks one. It uses the default the graph declares for the StatVar where one exists. Otherwise it prefers the DFO's own facet when that facet covers at least as many of the requested places as the broadest base Data Commons facet, and otherwise serves the facet that covers more places.

Who builds what

The pipelines build the StatVars and observations. For the CRS, a set of dbt (data build tool) SQL models maps each coded column to its dcid, sums matching records, mints the StatVar dcid and name, and writes observations and a provenance node for loading into the graph. Every other source follows the same pattern with its own columns.

The concepts those pipelines use, such as the class FinancialFlow, the property crsPurpose and the value CRSPurposeCode12220, come from the DFO ontology. The development finance ontology explains where they are defined and how source codes map to them.

Next

• The development finance ontology shows where FinancialFlow, crsPurpose, and the other concepts on this page are defined.
• Versions and snapshots explains how a question about these observations becomes a spec_id, and how a download becomes a content_version.