An Education Review Office report says most primary schools were working on the national standards in the first half of the year.
The report says 19% of schools were well prepared to assess children against the standards in reading, writing and maths, and another 61% were making progress.
But it also says that in the first two terms, most teachers had only some understanding of the standards and more than a quarter had little or no understanding.
Education Minister Anne Tolley says the figures are what she expected and most schools are doing a good job.
But the Principals Federation and the primary teachers union say most schools only made initial efforts to introduce the standards, and