Methodology
How we source, verify and present market data, supplier records and editorial content across the Commodities.tz network.
Market data
Every price series distinguishes its price type — farm-gate, auction, wholesale, export, international/reference, or indicative — along with market, location, grade/specification, currency and unit. We do not present prices of different types, grades, locations or marketing seasons as directly comparable. Each observation carries an observation date, a cited source, and the date we retrieved it. We never interpolate or invent data points to fill a chart: where the historical record is incomplete, the chart is incomplete, and we say so.
Supplier verification levels
- Listed — publicly discovered (e.g. via a business registry, trade directory or the supplier's own public materials) but not independently confirmed by us.
- Source-confirmed — corroborated by a credible public industry or government source (a commodity board register, an export directory, official statistics), which we cite on the supplier's profile.
- Verified — has completed the Commodities.tz verification process (in development). We do not label a supplier "Verified" simply because it has a website or was easy to find.
Sourcing priorities
We prioritise Tanzanian primary sources — commodity boards, ministries, the National Bureau of Statistics, the Zanzibar Office of the Chief Government Statistician, and the Tanzania Trade Development Authority — supplemented by international references such as FAOSTAT, UN Comtrade, the International Trade Centre, and the relevant international commodity organisations. We do not build claims primarily from generic blogs or unsourced aggregator sites.
Corrections
If you believe something on this network is inaccurate or out of date, please use our Corrections page — we review every report.