To calculate the value of the indicators and insure the integrity of the results, WRI is committed to using the most robust and widely accepted datasets in the public domain. WRI undergoes a rigorous data selection and validation process that relies heavily on external expert consultation. Expert consultation is carried out by convening basin-specific Advisory Groups that provide advice and recommendations on the selection of datasets, as well as detailed information on the data limitations and anomalies. A basin Advisory Group is composed in its entirety of river basin experts - from governments, NGO's, and academic institutions - many of whom are experienced researchers or data providers.