Feedback and other information collected at this time were then used to inform preparation of the field trial instruments. Reviews of the questionnaires by NPMs and experts in questionnaire design also fed into development of the field trial instruments. In addition, the TALIS Technical Advisory Group (TAG) advised on and validated the operations, standards, planning, and processes for the pilot, field trial, and main survey. The group’s role provided an important element of quality assurance for TALIS 2018.