New NAPLAN figures came out this week, and their basis has been questioned once again.

The Australian Curriculum, Assessment and Reporting Authority (ACARA) says a study it commissioned on how much parents and principals value the My School website found some serious discontent.

ACARA found that more than 300 of about 10,000 public and private schools achieved above-average gains in NAPLAN scores compared to similar schools.

Part of the study used 10 focus groups — five with teachers and five with students — who had used the My School website in the last year.

It found that some parents believed “certain schools place greater emphasis on ‘coaching’ children for NAPLAN tests and/or exclude some less able children from the test”.

Parents said they were concerned about the reliability and validity of the NAPLAN number “on the basis that they do not reflect a holistic view of the school”.

“Those with a more negative view cite the too narrow perspective of schools' performance provided by My School (in particular the heavy focus on NAPLAN),” the research report said.

“[But], attitudes towards the website have become more positive over time, and fears such as the large-scale publication of league tables and negative outcomes for schools that perform not as well on NAPLAN have not eventuated.”

“Most parents are using My School only as a starting point in their decision making,” about their child’s education, it said.

Education Minister Christopher Pyne says “NAPLAN is a vital part of the education system”.

“It makes everyone accountable to students and to parents,” he said.

“By publishing test results all governments — state and territory — and the Commonwealth can see what progress we're making.

“As a diagnostic tool it is really important for teachers to see the weaknesses in their students and the strengths in their students.”