The home schooling teaching method, called unschooling, is seen as a natural learning approach, in which children decide what they learn and when and parents give them freedom to pursue their interests.

But a NSW upper house inquiry was highly critical of the method, doubting it could "achieve quality educational outcomes for the child".

A report from the state's parliamentary inquiry into home schooling, prompted by revelations that there could be as many as 10,000 children in NSW being taught at home even though only 3200 are formally registered, urged the NSW Board of Studies to commission research into unschooling.

"The committee is concerned that taken to its extreme, children who are unschooled may not achieve even basic levels of literacy and numeracy. The application of unschooling may constitute educational neglect," the inquiry's report said.

But the government's response to the report, tabled last week in state parliament and signed off by Mr Baird, said it did not support the inquiry's recommendation for independent research into unschooling. The Home Education Association would be better placed to investigate the method, the government said.

The Home Education Association told the inquiry that a survey of home schooling parents showed they used a variety of approaches to educate their children, with about 15 per cent unschooling, 31 per cent using natural learning methods and 27 per cent were "eclectic home schoolers" using a mix of teaching styles.

In its response, the state government agreed to explore allowing home-schooled children to attend public schools part-time but would also not agree to further research into the outcomes of home schooling, arguing only 10 per cent of registered home schoolers choose to participate in NAPLAN.

​"The results of this self-selected group could not be generalised across the population of home schooled children, making further research into the outcomes of home schooling difficult," the response said.

The deputy chairman of the committee, Greens MP John Kaye, said "subjecting children to unschooling raises serious educational and welfare issues" yet Mr Baird did not want any further independent research into its consequences.

"It appears that just asking the questions is too perilous for the Premier and the extreme end of the home-schooling constituency he seems to be protecting," Dr Kaye said.

Dr Kaye said the committee felt there was a lack of objective research on home schooling in Australia and wanted the NSW government to fill that void.

"It is highly unusual for the Premier to sign a government response to an inquiry. This time it looks like he is meddling in a policy area that is increasingly of interest to his conservative Christian power base," Dr Kaye said.

A spokesman for the Education Minister, Adrian Piccoli, who is responsible for home schooling, said the Premier signed off on the government's response because it was a "whole of government response".