AidData engages in a variety of data collection and value addition activities to publish its ever-expanding suite of data products. Data collection takes place along two distinct product lines: Aggregate Data (or data represented as a single, composite value) and Project-Level Data (or data consisting of distinct, project activities with accompanying project information). AidData's data is sourced from various locations, including but not limited to the OECD-DAC's Creditor Reporting System (CRS), donor systems (such as official data from individual donor governments), and recipient systems (such as Aid Information Management Systems). Value addition activities include (1) activity and purpose coding, (2) geocoding (to produce our expanding repository of sub-national, geospatial research datasets) (3) data curation (the linking, deduplication and presentation of project records gathered from different sources or data collection activities), and (4) data quality assurance (the transformation and verification of data according to standard AidData practice). AidData also collects official project-level data on the development finance activities of non-OECD bilateral and multilateral donors, as well as data on Chinese development finance, collected using AidData's unique Tracking Under-reported Financial Flows (TUFF) methodology.