This may seem obvious, but it isn't. Many critics of television, to this day, argue that what's dangerous about TV is that it is addictive, that children and even adults watch it like zombies. According to this view, it is the formal features of television — violence, bright lights, loud and funny noises, quick editing cuts, zooming in and out, exaggerated action, and all the other things we associate with commercial TV — that hold our attention. In other words, we don't have to understand what we are looking at, or absorb what we are seeing, in order to keep watching. That's what many people mean when they say that television is passive. We watch when we are stimulated by all the whizzes and bangs of the medium. And we look away, or turn the channel, when we are bored.

What the pioneering television researchers of the 1960s and 1970s — in particular, Daniel Anderson at the University of Massachusetts — began to realize, however, is that this isn't how preschoolers watch TV at all. "The idea was that kids would sit, stare at the screen, and zone out," said Elizabeth Lorch, a psychologist at Amherst College. "But once we began to look carefully at what children were doing, we found out that short looks were actually more common. There was much more variation. Children didn't just sit and stare. They could divide their attention between couples of different activities. And they weren't being random. There were predictable influences on what made them look back at the screen, and these were not trivial things, not just flash and dash." Larch, for instance, once reedited an episode of SesameStreet so that certain key scenes of some of the sketches were out of order. If kids were only interested in flash and dash, that shouldn't have made a difference. The show, after all, still had songs and Muppets and bright colors and action and all the things that make Sesame Street so wonderful. But it did make a difference. The kids stopped watching. If they couldn't make sense of what they were looking at, they weren't going to look at it.

In another experiment, Lorch and Dan Anderson showed two groups of five-year-olds an episode of SesameStreet. The kids in the second group, however, were put in a room with lots of very attractive toys on the floor. As you would expect, the kids in the room without the toys watched the show about 87 percent of the time, while the kids with the toys watched only about 47 percent of the show. Kids are distracted by toys. But when they tested the two groups to see how much of the show the children remembered and understood, the scores were exactly the same. This result stunned the two researchers. Kids, they realized, were a great deal more sophisticated in the way they watched than had been imagined. "We were led to the conclusion," they wrote, "that the five-year-olds in the toys group were attending quite strategically, distributing their attention between toy play and viewing so that they looked at what for them were the most informative parts of the program. This strategy was so effective that the children could gain no more from increased attention."

If you take these two studies together — the toys study and the editing study — you reach quite a radical conclusion about children and television. Kids don't watch when they are stimulated and look away when they are bored. They watch when they understand and look away when they are confused. If you are in the business of educational television, this is a critical difference. It means if you want to know whether — and what — kids are learning from a TV show, all you have to do is to notice what they are watching. And if you want to know what kids aren't learning, all you have to do is notice what they aren't watching. Preschoolers are so sophisticated in their viewing behavior that you can determine the stickiness of children's programming by simple observation.

The head of research for Sesame Street in the early years was a psychologist from Oregon, Ed Palmer, whose specialty was the use of television as a teaching tool. When the Children's Television Workshop was founded in the late 1960s, Palmer was a natural recruit. "I was the only academic they could find doing research on children's TV," he says, with a laugh. Palmer was given the task of finding out whether the elaborate educational curriculum that had been devised for Sesame Street by its academic advisers was actually reaching the show's viewers. It was a critical task. There are those involved with Sesame Street who says, in fact, that without Ed Palmer the show would never have lasted through the first season.

Palmer's innovation was something he called the Distracter. He would play an episode of Sesame Street on a television monitor, and then run a slide show on a screen next to it, showing a new slide every seven and a half seconds. "We had the most varied set of slides we could imagine," said Palmer. "We would have a body riding down the street with his arms out, a picture of a tall building, a leaf floating through ripples of water, a rainbow, a picture taken through a microscope, an Escher drawing. Anything to be novel that was the idea." Preschoolers would then be brought into the room, two at a time, and told to watch the television show. Palmer and his assistants would sit slightly to the side, with a pencil and paper, quietly noting when the children were watching Sesame Street and when they lost interest and looked, instead, at the slide show. Every time the slide changed, Palmer and his assistants would make a new notation, so that by the end of the show they had an almost second-by-second account of what parts of the episode being tested managed to hold the viewers' attention and what parts did not. The Distracter was a stickiness machine.

"We'd take that big-sized chart paper, two by three feet, and tape several of those sheets together," Palmer says. "We had data points, remember, for every seven and a half seconds, which comes to close to four hundred data points for a single program, and we'd connect all those points with a red line so it would look like a stock market report from Wall Street. It might plummet or gradually decline, and we'd say whoa, what's going on here. At other times it might hug the very top of the chart and we'd say, wow, that segment's really grabbing the attention of the kids. We tabulated those Distracter scores in percentages. We'd have up to 100 percent sometimes. The average attention for most shows was around 85 to 90 percent. If the producers got that, they were happy. If they got around fifty, they'd go back to the drawing board."

Palmer tested other children's shows, like the Tom andJerry cartoons, or Captain Kangaroo, and compared what sections of those shows worked with what sections of Sesame Street worked. Whatever Palmer learned, he fed back to the show's producers and writers, so they could fine-tune the material accordingly. One of the standard myths about children's television, for example, had always been that kids love to watch animals. "The producers would bring in a cat or an anteater or an otter and show it and let it cavort around," Palmer says. "They thought that would be interesting. But our Distracter showed that it was a bomb every time." A huge effort went into a SesameStreet character called the Man from Alphabet, whose specialty was puns. Palmer showed that kids hated him. He was canned. The Distracter showed that no single segment of the Sesame Street format should go beyond four minutes, and that three minutes was probably optimal. He forced the producers to simplify dialogue and abandon certain techniques they had taken from adult television. "We found to our surprise that our preschool audience didn't like it when the adult cast got into a contentious discussion," he remembers. "They didn't like it when two or three people would be talking at once. That's the producers' natural instinct, to hype a scene by creating confusion. It's supposed to tell you that this is exciting. The fact is that our kids turned away from that kind of situation. Instead of picking up on the signal that something exciting is going on, they picked up on the signal that something confusing is going on. And they'd lose interest.