The birth marked the turning point in his teaching style. He began to judge the success of his lessons in a more personal way. "I found myself asking 'is this the sort of classroom experience I would want my daughter to have?' I began to see every boy and girl as somebody's son or daughter." That every child should get a good deal, no matter how shy, became all-important and he became less tolerant of disruptive children.
Karl Turner has been teaching for 15 years, seven of them in his present school. Over that time he has honed his art as performer and believes that performance is essential to creating an atmosphere of confidence in a classroom. "I see each lesson as a little performance. There is a correlation between acting and being good in the classroom," he says.
"I use a lot of body language. I move around the room a lot. By doing this I am putting out the message: 'This is my room and I am in total control of what's going on'. That makes pupils feel confident that I am doing something worthwhile. It also prevents disruption.
"In college we were given a lot of stuff about democracy in classrooms, but that doesn't work unless the basic premise that the teacher is in control is understood. Without control, organisation and discipline, everything else is just chaos. You have to get an atmosphere where children feel safe."
Although Karl Turner studied biology, he is more interested in the business of teaching. However, there are few children, he says, who are not interested in the natural world. "It is our job to foster that natural interest. I use stories a lot. I ham them up; I act them out."
The use of his voice is fundamental in both motivating and disciplining children. Once in a while he allows himself to show real anger. "I do go berserk, and children know that it can be a very unpleasant thing. Going berserk is part of the performance, not part of the failure. It is important for children to see how upset teachers can be."
Karl Turner was a grammar school boy from Walsall who opted out after an initial period at university. He felt uncomfortable with his "privileged" education and took a series of short-stay jobs, as a market barrow boy and a hospital technician, before eventually plumping for teaching.
The support of an older teacher got him through the first two years. "At the end of the day, I would sometimes collapse in floods of tears. I began to think 'I just can't hack this'. Children can be so cruel without realising it. "
As a crucial first step he employed rules he knew he could stick to and avoided unnecessary confrontation. He feels it unnecessary, for example, for pupils to line up in silence outside a classroom. "It's something you've got to stick to every time and offers potential for conflict before the lesson has even started. At the start of a lesson, my kids take their textbooks and exercise books from the front of the class, they find their desks, take off their coats, I sit down to take the register and up to this point I haven't spoken a word. Then I say 'Good morning' to take the register and that's when I want them quiet. It's for a reason and they know it.
"Part of the performance is manipulating the audience and knowing when to pick a kid up and when to let things go, always keeping something in reserve. To an outsider my lessons would appear astonishingly informal, but that is because there is a structure of authority in place."
He uses the work of able pupils in science as an example to be followed by others and always displays the results of class tests. "One of our LEA advisers thought this was demotivating, but kids are interested in their position in the class. Do you really think that less able children don't know who they are? Or that the bright kids don't know who the less able ones are? I take a low-ability group and I say 'We are all here because we have a difficulty and I am going to help you get better'. It is best out in the open. I have a boy who has a huge amount of difficulty with spelling. I get kids on his bench to help him - I don't stigmatise it but I do bring it out into the open."