The segments featuring children are mini-feature stories, and, because of the in-built repeats in Teletubbies, they make up a substantial part of each programme. The repeat is designed to provide children with the opportunity to take in more details and absorb the experience.

Our aim is to present the child’s world back to them, so we have to listen, watch, and tune in to how children perceive the world. To do this we need a very strong sense of audience, because our 18-month-old viewer is very different from our two, three and four-year-olds. Giving the child’s voice such prominence is, we feel, a pioneering approach to programme-making with young children.

All of our films come from observing and meeting children, in homes, nurseries and playgroups. I see what they enjoy and what generates discussion. For example, I spent one session in a nursery making a puppet theatre. Later I recorded a film with some of those nursery children making shadows using just a sheet and a clothes horse.

Some of the subjects are simplicity itself, such as crunching through leaves or experiencing the rain dripping down an umbrella or down one’s nose. They reflect children’s acute sense of hearing, smell and touch, and their awareness of the world around them.

Sometimes the segments take an activity which children enjoy and extend it. So although many children enjoy block play, not many get to help their daddy repair a dry-stone wall, with all the co-ordination involved in making the three-dimensional jigsaw puzzle fit together. Viewers understand the activity and are interested to see it in a new context. Similarly, many children love going to the car-wash, so one of our films showed how a double-dec ker bus is washed.

Some four-year-olds have started school, but not many will go to school by boat like Sam, who lives in the Scilly Isles. The principle is simple: start with something the children know and are enthusiastic about, and extend the experience.

Organisations are often helpful; for example, the London Cycling Campaign tipped me off about Ned, a two-year-old who adores his bike. Because his father, Nigel, works profession ally with bikes, Ned is growing up with a great deal of confidence and enjoyment in pumping up tyres and learning about hammers and spanners.

These films are what happens, as the psychologist Vygotsky might have said if he had ever seen Teletubbies, when work develops a sense of flow and becomes play. The learning is intrinsic to the experience.

Other subjects are chosen in order to ensure a wide range of educational experiences, so there is a great deal of numeracy in our number films, and natural history in our animal films.

I have made films to represent the diversity of culture in this country. These have been directly linked to festivals such as Diwali or Hanukkah, but in an engaging way. For example, in our Diwali film we visit a gorgeous mandir (Hindu temple) and look at the carved animals and dancers on the pillars. To reflect the Jewish festival of Hanukkah we show Elly, Aaron and Shimmy’s collection of Sev Yvon, spinning tops which are a traditional gift that they receive every year. These films introduce other cultures by using material that young children find meaningful. We have distilled the complex adult world to its essence.

The direct relationship that the children have with the lens is one of the innovations of Teletubbies, and a way of involving young viewers. When we started making these films, we developed different techniques for introducing the children to the camera. We have used small digital video cameras, which are unobtrusive, and some directors even dressed up the full-sized Beta 400 camera with arms and legs on its “body” so that the children could relate to it. I have tried sticking small favourite objects such as toy dinosaurs above the lens to remind the children where to look, or alternatively giving the camera a name; Fred is popular.

By now most children I meet know that their films are shown on the Teletubbies’ tummies, so the best approach seems to be to give the children hands-on experience. We let them have a good look down the viewfinder. Children quickly grasp how to look up into the lens, where they can often see their own reflections. Now I simply talk about the camera as the camera, and the lens as the eye of the camera. These children were born in a technologi cal age; they speak technological language.

Sometimes, in order to show an activity in more detail, we ask children to repeat what they are doing. For example, Humaad’s father runs a shop, and Humaad likes to help with shelf-stacking and labelling. At one stage the director asked Humaad to do a bit more labelling so that they could do some close-ups. He did not want to, because in his eyes he had done that already. So the enterprising director suggested that he might like to label her instead. To get this shot she lay on the floor out of view of the camera, and Humaad happily labelled all down her arm.

We work at the children’s pace. The children get tired, thirsty and need the loo or a cuddle from mummy. When this happens we stop filming and we work around them. This gives the filming a momentum of its own. Only once - when the tide was coming in at the seaside - did we ask the children to carry on for a bit longer.

A vital part of the process is to test our films with pre-school children.We see how they respond, repeating dialogue from the films, discussing it; and we watch their body language. It is highly satisfying to see if a film is working well - the children repeat actions and can become very animated. If a film does not work with the children, or hold their attention, then it won’t be used. This may not be the most cost-effective way of making programmes, but it is keeping faith with children.

We often go back to the children after we have edited the film to record additional commentary. This is done after viewing the film with them. They usually adore seeing themselves on video and are very good at telling the story of what they were doing, using either the present or past tense.

These children are not fazed by all the technological apparatus and understand that their voice goes down a wire on to a tape that will be edited into their film. I say “their film” because I do think that children have ownership of these films. No wonder the Teletubbies are watching!

Penny Lawrence directs films starring under-fives for the Teletubbies series, which is made by Ragdoll Productions for the BBC