For SDGs: classification of indicators regarding their methodological development and the feasibility to collect data from member countries.
- Tier 1: Indicator conceptually clear, established methodology and standards available and data regularly produced by countries
- Tier 2: Indicator conceptually clear, established methodology and standards available but data are not regularly produced by countries
- Tier 3: Indicator for which there are no established methodology and standards or methodology/standards are being developed/tested.
As of 21 December 2016: The updated tier classification contains 83 Tier I indicators, 59 Tier II indicators and 83 Tier III indicators. In addition to these, there are 5 indicators that have multiple tiers (different components of the indicator are classified into different tiers). The lowest tier was entered in ADAPT for these.