Cafodd y Rhaglen Wirio Allanol Genedlaethol ei chyflwyno yn dilyn ymgynghoriad cyhoeddus yn ystod tymor y Gwanwyn 2015. Diben y Rhaglen oedd cryfhau cywirdeb a chysondeb asesiadau athrawon ar ddiwedd Cyfnodau Allweddol 2 a 3.
The National Programme of External Verification was introduced following public consultation in Spring 2015. The Programme was designed to strengthen the accuracy and consistency of teacher assessments at the end of Key Stages 2 and 3.