Children start tuition young but when they hit their teenage years, extra classes become less important. The nature of tuition also changes over the course of a child's schooling, with group classes the preferred choice when the child is in primary school. When he hits secondary school, one-on-one tuition becomes more common.

These are some of the findings from a large-scale survey that looked at the growing prevalence of tuition in Singapore.

Nearly eight in 10 households with primary school children have tuition, compared with about six in 10 for households with secondary school students.

The door-to-door survey conducted by The Straits Times and research firm Nexus Link polled 501 households with children from preschool to post-secondary levels.

Out of 347 households with primary school children, 79.3 per cent had tuition. And of the 173 households with secondary school children, 61.8 per cent had tuition.

Mr Yee Kian Toung, 45, a tutor of eight years who specialises in mathematics, said tuition is viewed as a must-have at the primary level to help prepare pupils for the Primary School Leaving Examinations (PSLE), which is a "do-or-die exam and a ticket to a good school. Parents will do their best to maximise their kid's potential".

Mr Yee, a former Ministry of Education teacher, said that at the secondary school level, "parents are more hands-off and tend to react only when the child's grades slip".

Madam Yeo Ai Li, 43, sends her Primary 5 daughter for English and Chinese tuition. Her son, 14, stopped going for tuition when he started secondary school.

She said he spends longer hours in school now and tuition would leave him with less free time. But her daughter needs tuition to help her cope with the upcoming PSLE.

The study also found that parents mainly chose private group tuition, which includes tuition centres, for their primary school children. About 58.9 per cent of parents with such children opted for private group classes, against 34.2 per cent going for individual tuition.

At the secondary level, it appears that those who have tuition preferred one-on-one lessons, at about 43.5 per cent. The percentage of those with private group tuition was lower at 38.9 per cent.

Housewife Colleen Teo, 43, said she prefers group tuition for her younger son, who is in Primary 4. Her older son, who is in Primary 6, has individual tuition only because he has Asperger's Syndrome and requires special attention. She said the "interaction with his peers" motivates her younger son, and that a tuition centre has more resources to make lessons interesting.