Statistics released by ERO show the number of supplementary reviews conducted by the office had dropped from six in the year ended June 2007, to four in the year ended June 2008.
A supplementary review is generally undertaken when ERO has concerns about the performance of a school and signals a follow-up review within 12 months.
It has terms of reference that relate to the previous review and form the basis for the supplementary evaluation.
Nationwide, the number of supplementary reviews had increased from 116 in 2007 to 119 in 2008.
Otago Primary Principals Association president and former ERO review officer Steve Hayward said the number of supplementary reviews in Otago was just a fraction of the national figures, and was delighted with the continued downward trend of Otago statistics.
"It's tremendous that so few schools have needed so few supplementary reviews. It's as close to zero as you can get.
"The numbers in Otago are quite low compared to other parts of New Zealand. They are also much lower in Otago than they were 10 years ago.
"We have some fantastic schools in the South Island. We're very fortunate to have very good schools in our area."
Mr Hayward said the improvement was most likely caused by a shift in focus by ERO staff from compliance-related issues such as "which way the school gates should swing" to student achievement issues.
"The comments I hear from people in the community is that they would be happy for their kids to be at any school in Otago."
