Outspoken - Changes to teacher training and the way subjects are taught to low-achievers could help improve New Zealand's performance in prestigious international tests, experts say.
Researchers and a school principal told RNZ's Outspoken that relatively poor results in the tests did not reflect an erosion of quality in the school system.
New Zealand's scores in the Programme for International Student Assessment (PISA) for 15-year-olds were its lowest ever, and it continued to rank poorly in the Trends in International Maths and Science Study (TIMSS) for 10- and 14-year-olds.
University of Auckland education professor Stuart McNaughton said scores for other English-speaking nations fell in the latest round of PISA.
He said schools in New Zealand and overseas were increasingly tailoring what they taught to each individual and that could have contributed to the decline in scores if some students were exposed to a more limited curriculum than others.
"It looks like across English-speaking countries, quite a lot of the variation in achievement is attributable to this within-school variation in how much we teach and provide for different students," he said.
New Zealand's lowest scores in both the PISA and TIMSS tests were in maths.
Professor McNaughton said teachers lacked training and confidence in maths and New Zealand had a lot fewer teachers at Year 5 and Year 9 with specific maths qualifications.
"Our teachers are less confident about teaching algebra and geometry and cover those areas less, according to the PISA and TIMSS data, and not surprisingly our children, our students achieve less well specifically in those areas."
Edgewater College principal Allan Vester said low-achievers in maths needed more help earlier in their schooling and a specific intervention would be helpful.
"In the case of reading we have Reading Recovery and we put that into place at quite a young age. In fact the subject which we're least confident about teaching is maths - there's no Maths Recovery. You would think that the area where teachers might actually appreciate the extra support with students who are not doing so well would be the subject which they feel least confident in themselves."
Mr Vester said, because of the NCEA system, 15-year-olds encountered fewer two-hour exams than they used to under previous systems and that might have contributed to the long-term decline in New Zealand's PISA scores.
"A lot less emphasis is now placed on those external examinations and students actually sit less long two, three-hour exams tests than they previously did and I did wonder whether to some extent for many of our students now sitting PISA this is probably the longest time they've sat and done a test."
Council for Educational Research senior researcher Cathy Wylie said schools needed more support from the wider education system if scores were going to improve.
"We still don't have the kind of support that teachers need and the resources that they do have in other systems where you do think about providing some guidance and support and giving teachers time away from teaching to sit down and work together."
Dr Wylie said improvements in the PISA scores of the poorest 25 percent of students indicated greater attention to that group was paying off.
Outspoken is a series in which RNZ's experienced correspondents host debates on some of the top issues of the year - and the year ahead. Check back for new episodes this week here.