When she wanted to know how to spell ''love'', she asked her mother, Lauren Fisher, who reminded her how to form the letters. ''At this point, it's irrelevant that she doesn't know how to write a Q or a G,'' she said.

''When she needs to know those letters, she will ask how to form them.''

Fisher adopts the same teaching method for all of her four daughters aged between three and seven - none of whom go to school.

Instead, they are unschooled, which is a method of home schooling in which a child is free to pursue the things they want to learn without having topics and tasks forced upon them. To be legal in NSW, the method has to be approved by an inspector from the Board of Studies.

Moreover, Fisher and her daughters are full-time travellers and live out of a bus, which she says provides added learning opportunities.

''We engage in life - household chores, long-term projects, outings, visits and down-time - and along the way my girls approach problems with creativity and a quest for answers,'' she said.

More than 50,000 Australian children were home schooled last year, according to a report on ABC Radio National's Background Briefing.

But there are no accurate figures on how many children are unschooled in Australia, according to Beverley Paine, who runs the Unschool Australia website.

Up to 20 per cent of home educated children may be unschooled, she said, while many others are taught using some elements of unschooling methodology.

Paine, who unschooled her three children between 1985 and 2004, said their learning was integrated into everyday life: ''Lessons were generally spontaneous and met the child's immediate learning need.''

Paine, from Yankalilla in South Australia, kept records of her children's progress, but she said ''keeping pace with peers was not as important as the children learning what they needed to learn at any particular point in their development as people''.

Home-schooled children must be registered in NSW and taught in accordance with a syllabus provided by the Board of Studies.

Parents may adopt a teaching method such as unschooling, according to a spokeswoman for the Board of Studies, Julie-Anne Scott. But she said: ''Regardless of philosophy or teaching methodology, the parent must demonstrate that the requirements for registration are met.''

A senior lecturer in Monash University's Faculty of Education, Dr David Zyngier, does not support any form of unschooling because the vast majority of parents are not capable of teaching their children to read, write or be numerate.

''Children on their own without external intervention will never learn to read and write or do mathematics, the three most difficult things that any child will ever learn,'' he said.

''That is why we leave these things to well-educated professionals. That is why we no longer go to witch doctors for medical issues or try and fix our cars, fix faulty electrical systems ourselves.''

Dr Zyngier said there is no robust evidence that unschooled children are capable of the same academic achievement as measured by year 12 results. Unschooling has laudable aims, but Dr Zyngier said ''powerful learning like these approaches need to be offered in all schools to all children''. ''But such learning approaches if taking place outside of the school will only be possible in middle-class families,'' he said.

Samuel Lewis, 13, was taken out of school last year by his parents and unschooled along with his siblings Georgia, 16, and Thomas, 11.

Samuel's mother, Penny Lewis, said unschooling gives her children the opportunity to explore their own interests and learn without the restrictions of a curriculum. Lewis said each of her children learnt differently by watching YouTube and DVDs, experimenting with building projects, computer programming, sewing and cooking.

Physical exercise and leisure activities are also an integral part of her children's unschool day.

''There are no early morning starts in our home,'' she said. ''With two teens and a tween, sleep-ins are welcomed and encouraged.''

However, Samuel has decided to return to high school mainly because he misses his friends.

''My friends miss me, but because it's been a year they have moved on,'' he said.