The Qualifications Authority is refusing to accept NCEA internal assessments from a Northland school and is monitoring six others because of shortcomings in their assessment practices.
The authority's audits show problems have ranged from poor teaching and marking to failure to make sure students' work is their own.
It says Te Kura Kaupapa o Kaikohe is the only school with conditions on its assessment of students. It says teachers there awarded results students might not have achieved and assessments are currently done by another school - but the kura has improved and that condition is likely to be lifted next term.
The six other schools are on one-year audit cycles, mostly because of problems with systems and procedures, though an audit of one of the schools last year criticises poor teaching that disadvantages its students.
Secondary Principals Association president Tom Parsons says the low number of schools on the authority's watchlist proves NCEA is working well, but small schools need more help to meet its rules.
He says smaller schools often have single-teacher departments, making it is difficult for teachers to get their marking of student work checked, and it would help if the schools had the money to get that done more often.