Hefyd barnodd Estyn fod rhagolygon Merthyr Tudful ar gyfer gwella yn anfoddhaol. Nid yw uwch swyddogion ac aelodau etholedig y cyngor wedi herio tanberfformiad neu ddeilliannau gwael i ddysgwyr. Nid yw swyddogion wedi rhoi adroddiadau i aelodau sy’n dadansoddi data am berfformiad yn ddigon da i nodi cynnydd a meysydd allweddol ar gyfer gwella. Canfu tîm yr arolygiad nad oes gan yr awdurdod lleol broses hunanwerthuso gadarn a pharhaus ar gyfer ei wasanaethau addysg. Nid yw ychwaith wedi ymateb yn ddigon da i argymhellion arolygiadau blaenorol, gan gynnwys rhai sy’n dyddio’n ôl i 2004. Daeth tîm yr arolygiad i’r casgliad nad oes gan yr awdurdod systemau effeithiol i farnu a yw mentrau a gwasanaethau yn cael effaith gadarnhaol ar blant a phobl ifanc neu’n cynnig gwerth da am arian.
Estyn also judged Merthyr’s prospects for improvement as unsatisfactory.  Senior officers and elected members of the council have not challenged underperformance or poor outcomes for learners.  Officers have not provided reports to members that analyse performance data well enough to identify progress and key areas for improvement.  The inspection team found that the local authority does not have in place a robust and continuous self-evaluation process for its education services.  Nor has it responded well enough to the recommendations from past inspections including those going back to 2004.  The inspection team concluded that the authority lacks effective systems to judge whether initiatives and services have a positive impact on children and young people or offer good value for money.