"The current picture is that there isn't any clear data that gives the people that need to know to change the situation a picture of what's going on in terms of bullying in schools," said commissioner David Rutherford. "Without data how do you know that what you're doing is working?"
Latest bullying research indicated New Zealand has not been reducing bullying in primary schools, a negative pattern evident since 1994.
Mr Rutherford said it was important for schools to understand the extent of the problem.
"The best sign that a school has a bullying problem is if they say they don't have one."
However, Minister of Education Hekia Parata said all schools were supposed to already have bullying policies and be dealing with issues as they occurred.
"Mandatory collecting of bullying data could well distract schools from dealing with the day to day practicalities of supporting kids to treat one another with tolerance and respect."
Unions and principals felt while data collection was good, it should only be for schools to use, and did not need to be nationwide.
President of the NZEI teaching union Louise Green said it was concerned young children would be labelled as "bullies" and that would follow them through the system.
Head of the New Zealand Principals Federation Denise Torrey was concerned by how the information would be used. "Is it just another stick to beat the sector over the head with?" she asked. President of the PPTA union Angela Roberts said while data was helpful and she would support information being shared among schools, there were pitfalls to any kind of wider database that may be made public, for example as a league table.
"Schools aren't going to put their hands up and say 'we've got a problem' because it's a competitive environment and they know that if they do that a whole bunch of kids will leave," she said. "Schools' reputation is important."
Father of bullying victim Raybane Hume-Kinzett said he believed a lot of bullying was going unmonitored.
Raybane, from Carterton, tried to commit suicide in 2013 after taunts from classmates about his eczema and weight. He was 11.
"Schools are more worried about bad publicity than the kids' care," Paul Kinzett said.
Mr Kinzett said schools needed to teach bullying as part of the curriculum.
"They should be trying to teach kids to identify bullying early on."
Signs your child may be being bullied
• Anxious or negative about school
• Off school or classes because they've been sick a lot
• Reluctant to join in certain activities
• Has bruises and won't give you a straight answer about how they got them
• Talks about "nobody likes me" or "I haven't got any friends"
• Talks about wanting to hurt someone or get back at someone
Source: Ministry of Education
Where to get help
Suicide Crisis Helpline 0508 828 865 (24 hours)
Lifeline 0800 543 354 (available 24/7)
Youthline 0800 376 633
Kidsline 0800 543 754 (4pm to 6pm weekdays)
Depression helpline 0800 111 757 (available 24/7)
