Ar draws Cymru, mae llawer gormod o amrywiaeth yng nghyrhaeddiad dysgwyr rhwng ysgolion sydd â phroffiliau economaidd-gymdeithasol tebyg ac yn enwedig rhwng awdurdodau lleol sydd â nodweddion demograffig tebyg.
Across Wales, there is far too much variation in learner attainment between schools with similar socio-economic profiles and particularly between local authorities with similar demographic characteristics.