The core experience of monitoring for implementation that the 2030 agenda will build upon is the MDGs experience

Administrative data, existing at the local level, have always been fully used for decision-making purposes. 

Censuses representing one of the primary sources of data for the MDGs and covering the entire population are expensive to conduct and are not frequent.

One of the challenges with the MDGs was that there was a discrepancy between international and national standards and that data collected nationally was not always comparable, and missing out on some indicators.

Group on MDG Indicators (IAEG-MDGs).

Household surveys are frequently used, because they do not exclude any vulnerable groups.