Changes to the NCEA system which will see the grades "excellent" and "merit" added to certificates have been announced.

In another major change unveiled today, internal assessments will also show if a student has "not achieved" a required standard.

Education Minister Steve Maharey says the changes are an acknowledgement that the system could be improved and he believes the changes will give both students and employers a better understanding of ability. Mr Maharey says it will give a clear guide to students just how well they are doing, and will also tell employers what students cannot do.

Post Primary Teachers Association president Robin Duff says the higher grades are good news for high achievers. But he suggests the addition of the "not achieved" grade is a backward step as it moves away from the principal where achievement is the most important thing, rather than the lack of achievement.