The 2020 Update Leave Quality Control program was part of the Update Leave (UL) Operation. The UL operation consisted of enumerators visiting specific geographic areas to conduct dependent listing to update the address list, map data, and leave a 2020 Census questionnaire package.

During the 2020 Census UL Quality Control operation, quality control enumerators used traditional canvassing techniques to check basic collection units selected for follow-up in the field. They canvassed each assigned basic collection unit and checked that each address they saw on the ground matched the electronic address list shown in the canvassing software.

Quality control enumerators followed the same general procedures as production enumerators, with some variations. They began working at a randomly assigned location and worked a sample of addresses in a basic collection unit. In basic collection units with a smaller number of addresses, the sample included all the addresses in the unit.

These enumerators also worked with the address list information collected by the production enumerator. If the sample of addresses had more than the allowable number of errors for the basic collection unit, the quality control enumerator reworked the entire unit.

This report presents the results of the assement conducted on the 2020 Census UL Quality Control program, as well as recommendations for future listing operations.