Tipping Point: How Little Things Can Make a Big Difference

THREE
The Stickiness Factor
SESAME STREET, BLUE'S CLUES, AND THE EDUCATIONAL VIRUS

In the late 1960s, a television producer named Joan Gantz Cooney set out to start an epidemic. Her target was three-, four-, and five-year-olds. Her agent of infection was television, and the "virus" she wanted to spread was literacy. The show would last an hour and run five days a week, and the hope was that if that hour was contagious enough it could serve as an educational Tipping Point: giving children from disadvantaged homes a leg up once they began elementary school, spreading prolearning values from watchers to nonwatchers, infecting children and their parents, and lingering long enough to have an impact well alter the children stopped watching the show. Cooney probably wouldn't have used these concepts or described her goals in precisely this way. But what she wanted to do, in essence, was create a learning epidemic to counter the prevailing epidemics of poverty and illiteracy. She called her idea Sesame Street.

By any measure, this was an audacious idea. Television is a great way to reach lots of people, very easily and cheaply. It entertains and dazzles. But it isn't a particularly educational medium. Gerald Lesser, a Harvard University psychologist who joined with Cooney in founding SesameStreet, says that when he was first asked to join the project, back in the late 1960s, he was skeptical. "I had always been very much into fitting how you teach to what you know about the child," he says. "You try to find the kid's strengths, so you can play to them. You try to understand the kid's weaknesses, so you can avoid them. Then you try and teach that individual kid's profile… Television has no potential, no power to do that." Good teaching is interactive. It engages the child individually. It uses all the senses. It responds to the child. But a television is just a talking box. In experiments, children who are asked to read a passage and are then tested on it will invariably score higher than children asked to watch a video of the same subject matter. Educational experts describe television as "low involvement." Television is like a strain of the common cold that can spread like lightning through a population, but only causes a few sniffles and is gone in a day.

But Cooney and Lesser and a third partner — Lloyd Morrisett of the Markle Foundation in New York — set out to try anyway. They enlisted some of the top creative minds of the period. They borrowed techniques from television commercials to teach children about numbers. They used the live animation of Saturday morning cartoons to teach lessons about learning the alphabet. They brought in celebrities to sing and dance and star in comedy sketches that taught children about the virtues of cooperation or about their own emotions. Sesame Street aimed higher and tried harder than any other children's show had, and the extraordinary thing was that it worked. Virtually every time the show's educational value has been tested — and Sesame Street has been subject to more academic scrutiny than any television show in history — it has been proved to increase the reading and learning skills of its viewers. There are few educators and child psychologists who don't believe that the show managed to spread its infectious message well beyond the homes of those who watched the show regularly. The creators of Sesame Street accomplished something extraordinary, and the story of how they did that is a marvelous illustration of the second of the rules of the Tipping Point, the Stickiness Factor. They discovered that by making small but critical adjustments in how they presented ideas to preschoolers, they could overcome television's weakness as a teaching tool and make what they had to say memorable. Sesame Street succeeded because it learned how to make television sticky.

The Law of the Few, which I talked about in the previous chapter, says that one critical factor in epidemics is the nature of the messenger. A pair of shoes or a warning or an infection or a new movie can become highly contagious and tip simply by being associated with a particular kind of person. But in all those examples, I took it as given that the message itself was something that could be passed on. Paul Revere started a word-of-mouth epidemic with the phrase "The British are coming." It he had instead gone on that midnight ride to tell people he was having a sale on the pewter mugs at his silversmith shop, even he, with all his enormous personal gifts, could not have galvanized the Massachusetts countryside.

Roger Horchow, likewise, taxed all his friends about the restaurant his daughter took him to, performing the first step in creating a word-of-mouth epidemic. But obviously, for that epidemic to take off, the restaurant itself had to remain a good restaurant. It had to be the kind of restaurant that made an impact on the people who ate there. In epidemics, the messenger matters: messengers are what make something spread. But the content of the message matters too. And the specific quality that a message needs to be successful is the quality of "stickiness." Is the message — or the food, or the movie, or the product — memorable? Is it so memorable, in fact, that it can create change, that it can spur someone to action?

Stickiness sounds as if it should be straightforward. When most of us want to make sure what we say is remembered, we speak with emphasis. We talk loudly, and we repeat what we have to say over and over again. Marketers feel the same way. There is a maxim in the advertising business that an advertisement has to be seen at least six times before anyone will remember it. That's a useful lesson for Coca-Cola or Nike, who has hundreds of millions of dollars to spend on marketing and can afford to saturate all forms of media with their message. But it's not all that useful for, say, a group of people trying to spark a literacy epidemic with a small budget and one hour of programming on public television. Are there smaller, subtler, easier ways to make something stick?

Consider the field of direct marketing. A company buys an ad in a magazine or sends out a direct mailing with a coupon attached that they want the reader to clip and mail back to them with a check for their product. Reaching the consumer with the message is not the hard part of direct marketing. What is difficult is getting consumers to stop, read the advertisement, remember it, and then act on it. To figure out which ads work the best, direct marketers do extensive testing. They might create a dozen different versions of the same ad and run them simultaneously in a dozen different cities and compare the response rates to each. Conventional advertisers have preconceived ideas about what makes an advertisement work: humor, splashy graphics, and a celebrity endorser. Direct marketers, by contrast, have few such preconceptions, because the number of coupons that are mailed back or the number of people who calls in on an 800 number in response to a television commercial gives them an objective, iron-clad measure of effectiveness. In the advertising world, direct marketers are the real students of stickiness, and some of the most intriguing conclusions about how to reach consumers have come from their work.

In the 1970s, for example, the legendary direct marketer Lester Wunderman had a showdown with the Madison Avenue firm McCann Erickson over the Columbia Record Club account. Columbia was then — as it is now — one of the largest mail order clubs in the world, and Wunderman had handled the company's advertising since it was formed in the 1950s. Columbia decided, however, to hire McCann Co come up with a series of television commercials to support the direct-marketing print ads that Wunderman was creating. These were not late-night commercials with a toll-free 800 number. They were standard television spots designed simply to raise awareness. Understandably, Wunderman was upset. He had handled the Columbia account for twenty years and didn't like the idea of losing even a small part of the business to a competitor. Nor was he convinced that McCann's advertising would actually do Columbia any good. To settle the issue, he proposed a test. Columbia, he said, should run a full complement of the advertising created by his firm in the local editions of TV Guide and Parade magazine in twenty-six media markets around the United States. In thirteen of those markets, McCann should be allowed to air its "awareness" television commercials. In the other thirteen, Wunderman would air his own set of television commercials. Whoever's commercials created the greatest increase in response to the local TV Guide and Parade advertising would win the whole account. Columbia agreed, and after a month they tabulated the results. Responses in Wunderman's markets were up 80 percent, compared to 19.5 percent for McCann. Wunderman had won in a rout.

The key to Wunderman's success was something he called the "treasure hunt." In every TV Guide and Parade ad, he had his art director put a little gold box in the corner of the order coupon. Then his firm wrote a series of TV commercials that told the "secret of the Gold Box," Viewers were told that if they could find the gold box in their issues of Parade and TV Guide, they could write in the name of any record on the Columbia list and get that record free. The gold box, Wunderman theorized, was a kind of trigger. It gave viewers a reason to look for the ads in TV Guide and Parade. It created a connection between the Columbia message viewers saw on television and the message they read in a magazine. The gold box, Wunderman writes, "Made the reader/viewer part of an interactive advertising system. Viewers were not just an audience but had become participants. It was like playing a game… The effectiveness of the campaign was startling. In 1977 none of Columbia's ads in its extensive magazine schedule had been profitable. In 1978, with Gold Box television support, every magazine on the schedule made a profit, an unprecedented turnaround."

What's interesting about this story is that by every normal expectation McCann should have won the test. The gold box idea sounds like a really cheesy idea. Columbia was so skeptical of it that it took Wunderman several years to persuade them to let him try it. McCann, meanwhile, was one of the darlings of Madison Avenue, a firm renowned for its creativity and sophistication. Furthermore, McCann spent four times as much as Wunderman on media time. They bought prime-time slots for their space. Wunderman's ads were on in the wee hours of the morning. In the last chapter, I talked about how epidemics are, in part, a function of how many people a message reaches, and by that standard McCann was way ahead. McCann did all the big things right. But they didn't have that little final touch, that gold box that would make their message stick.

If you look closely at epidemic ideas or messages, as often as not the elements that make those sticky turn out to be as small and as seemingly trivial as Wunderman's gold box. Consider, for example, the so-called fear experiments conducted by the social psychologist Howard Levanthal in the 1960s. Levanthal wanted to see if he could persuade a group of college seniors at Yale University to get a tetanus shot. He divided them up into several groups, and gave all of them a seven-page booklet explaining the dangers of tetanus, the importance of inoculation, and the fact that the university was offering free tetanus shots at the campus health center to all interested students. The booklets came in several versions. Some of the students were given a "high fear" version, which described tetanus in dramatic terms and included color photographs of a child having a tetanus seizure and other tetanus victims with urinary catheters, tracheotomy wounds, and nasal tubes. In the "low fear" version, the language describing the risks of tetanus was toned down, and the photographs were omitted. Levanthal wanted to see what impact the different booklets had on the students' attitudes toward tetanus and their likelihood of getting a shot.

The results were, in part, quite predictable. When they were given a questionnaire later, all the students appeared to be well educated about the dangers of tetanus. But those who were given the high-fear booklet were more convinced of the dangers of tetanus, more convinced of the importance of shots, and were more likely to say that they intended to get inoculated. All of those differences evaporated, however, when Levanthal looked at how many of the students actually went and got a shot. One month after the experiments, almost none of the subjects — a mere 3 percent — had actually gone to the health center to get inoculated. For some reason, the students had forgotten everything they had learned about tetanus, and the lessons they had been told weren't translating into action. The experiment didn't stick. Why not?

If we didn't know about the Stickiness Factor, we probably would conclude that something was wrong with the way the booklet explained tetanus to the students. We might wonder whether trying to scare them was the appropriate direction to take, whether there was a social stigma surrounding tetanus that inhibited students from admitting that they were at risk, or perhaps that medical care itself was intimidating to students. In any case, that only 1 percent of students responded suggested that there was a long way to go to reach the goal. But the Stickiness Factor suggests something quite different. It suggests that the problem probably wasn't with the overall conception of the message at all, and that maybe all the campaign needed was a little gold box. Sure enough, when Levanthal redid the experiment, one small change was sufficient to tip the vaccination rate up to 28 percent. It was simply including a map of the campus, with the university health building circled and the times that shots were available clearly listed.

There are two interesting results of this study. The first is that of the 28 percent who got inoculated, an equal number were from the high-fear and the low-fear group. Whatever extra persuasive muscle was found in the high-fear booklet was clearly irrelevant. The students knew, without seeing gory pictures, what the dangers of tetanus were, and what they ought to be doing. The second interesting thing is that, of course, as seniors they must have already known where the health center was, and doubtless had visited it several times already. It is doubtful that any of them would ever actually have used the map. In other words, what the tetanus intervention needed in order to tip was not an avalanche of new or additional information. What it needed was a subtle but significant change in presentation. The students needed to know how to fit the tetanus stuff into their lives; the addition of the map and the times when the shots were available shifted the booklet from an abstract lesson in medical risk — a lesson no different from the countless other academic lessons they had received over their academic career — to a practical and personal piece of medical advice. And once the advice became practical and personal, it became memorable.

There are enormous implications in Levanthal's fear experiments and Wunderman's work for Columbia Records for the question of how to start and tip social epidemics. We have become, in our society, overwhelmed by people clamoring for our attention. In just the past decade, the time devoted to advertisements in a typical hour of network television has grown from six minutes to nine minutes, and it continues to climb every year. The New York-based firm Media Dynamics estimates that the average American is now exposed to 254 different commercial messages in a day, up nearly 25 percent since the mid-1970s. There are now millions of web sites on the Internet, cable systems routinely carry over 50 channels of programming, and a glance inside the magazine section of any bookstore will tell you that there are thousands of magazines coming out each week and month, chock-full of advertising and information. In the advertising business, this surfeit of information is called the "clutter" problem, and clutter has made it harder and harder to get any one message to stick. Coca-Cola paid $33 million for the rights to sponsor the 1992 Olympics, but despite a huge advertising push, only about 12 percent of TV viewers realized that they were the official Olympic soft drink, and another 5 percent thought that Pepsi was the real sponsor. According to a study done by one advertising research firm, whenever there are at least four different 15-second commercials in a two-and-a-half-minute commercial time-out, the effectiveness of any one 15-second ad sinks to almost zero. Much of what we are told or read or watch, we simply don't remember. The information age has created a stickiness problem. But Levanthal and Wunderman's examples suggest that there may be simple ways to enhance stickiness and systematically engineer stickiness into a message. This is a fact of obvious importance to marketers, teachers, and managers. Perhaps no one has done more to illustrate the potential of this kind of stickiness engineering, however, than children's educational television, in particular the creators of Sesame Street and, later, the show it inspired, Blue's Clues.

Sesame Street is best known for the creative geniuses it attracted, people like Jim Henson and Joe Raposo and Frank Oz, who intuitively grasped what it takes to get through to children. They were television's answer to Beatrix Potter or L. Frank Baum or Dr. Seuss. But it is a mistake to think of Sesame Street as a project conceived in a flash of insight. What made the show unusual, in fact, was the extent to which it was exactly the opposite of that — the extent to which the final product was deliberately and painstakingly engineered. Sesame Street was built about a single, breakthrough insight: that if you can hold the attention of children, you can educate them.

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.

"After the third or fourth season, I'd say it was rare that we ever had a segment below eighty-five percent. We would almost never see something in the fifty to sixty percent range, and if we did, we'd fix it. You know Darwin's terms about the survival of the fittest? We had a mechanism to identify the fittest and decide what should survive."

The most important thing that Palmer ever found out with the Distracter, though, came at the very beginning, before Sesame Street was even on the air. It was the summer of 1969 and we were a month and a half from air date," Lesser remembers. "We decided, let's go for broke. Let's produce five full shows — one hour each — before we go to air and we'll see what we've got." To test the shows, Palmer took them to Philadelphia and over the third week of July showed them to groups of preschoolers in sixty different homes throughout the city. It was a difficult period. Philadelphia was in the midst of a heat wave, which made the children who were supposed to watch the show restless and inattentive. In the same week, as well, Apollo 11 landed on the moon, and some children — understandably — seemed to prefer that historic moment to Sesame Street. Worst of all were the conclusions from Palmer's Distracter. "What we found," Lesser says, "almost destroyed us."

The problem was that when the show was originally conceived, the decision was made that all fantasy elements of the show be separated from the real elements. This was done at the insistence of many child psychologists, who felt that to mix fantasy and reality would be misleading to children. The Muppets, then, were only seen with other Muppets, and the scenes filmed on Sesame Street itself involved only real adults and children. What Palmer found out in Philadelphia, though, was that as soon as they switched to the street scenes, the kids lost all interest. "The street was supposed to be the glue," Lesser said. "We would always come back to the street. It pulled the show together. But it was just adults doing things and talking about stuff and the kids weren't interested. We were getting incredibly low attention levels. The kids were leaving the show. Levels would pop back up if the Muppets came back, but we couldn't afford to keep losing them like that." Lesser calls Palmer's results a "turning point in the history of Sesame Street. We knew that if we kept the street that way, the show was going to die. Everything was happening so fast. We had the testing in the summer, and we were going on the air in the fall. We had to figure out what to do."

Lesser decided to defy the opinion of his scientific advisers. "We decided to write a letter to all the other developmental psychologists and say, we know how you guys think about mixing fantasy and reality. But we're going to do it anyway. If we don't, we'll be dead in the water." So the producers went back and re-shot all of the street scenes. Henson and his coworkers created puppets that could walk and talk with the adults of the show and could live alongside them on the street. "That's when Big Bird and Oscar the Grouch and Snuffleupagus were born," said Palmer. What we now think of as the essence of SesameStreet — the artful blend of fluffy monsters and earnest adults — grew out of a desperate desire to be sticky.

The Distracter, however, for all its strengths, is a fairly crude instrument. It tells you that a child understands what is happening on the screen and as a result is paying attention. But it doesn't tell you what the child understands or, more precisely, it doesn't tell you whether the child is paying attention to what he or she ought to be paying attention to.

Consider the following two Sesame Street segments, both of which are called visual-blending exercises — segments that teach children that reading consists of blending together distinct sounds. In one, "Hug," a female Muppet, approaches the word HUG in the center of the screen. She stands behind the H, sounding it out carefully, then moves to the U, and then the G. She does it again, moving from left to right, pronouncing each letter separately, before putting the sounds together to say "hug." As she does, the Muppet Herry Monster enters and repeats the word as well. The segment ends with the Herry Monster hugging the delighted little-girl Muppet.

In another segment, called "Oscar's Blending," Oscar the Grouch and the Muppet Crummy play a game called "Breakable Words," in which words are assembled and then taken apart. Oscar starts by calling for C, which pops up on the lower left corner of the screen. The letter C, Oscar tells Crummy, is pronounced "cuh" Then the letters at pop up in the lower right-hand corner and Crummy sounds the letters out — "at," The two go back and forth — Oscar saying "cuh and Crummy "at" - each time faster and faster, until the sounds blend together to make cat. As this happens, the letters at the bottom of the screen move together as well to make "cat." The two Muppets repeat "cat" a few times and then the word drops from sight, accompanied by a crashing sound. Then the process begins again with the word bat.

Both of these segments are entertaining. They hold children's attention. On the Distracter, they score brilliantly. But do they actually teach the fundamentals of reading? That's a much harder question. To answer it, the producers of Sesame Street in the mid-1970s called in a group of researchers at Harvard University led by a psychologist named Barbara Flagg who were expert in something called eye movement photography. Eye movement research is based on the idea that the human eye is capable of focusing on only a very small area at one time — what is called a perceptual span. When we read, we are capable of taking in only about one key word and then four characters to the left and fifteen characters to the right at any one time. We jump from one of these chunks to another, pausing — or fixating — on them long enough to make sense of each letter. The reason we can focus clearly on only that much text is that most of the sensors in our eyes — the receptors that process what we see — are clustered in a small region in the very middle of the retina called the fovea. That's why we move our eyes when we read: we can't pick up much information about the shape, or the color, or the structure of words unless we focus our fovea directly on them. Just try, for example, to reread this paragraph by staring straight ahead at the center of the page. It's impossible.

If you can track where someone's fovea is moving and what they are fixating on, in other words, you can tell with extraordinary precision what they are actually looking at and what kind of information they are actually receiving. The people who make television commercials, not surprisingly, are obsessed with eye tracking. If you make a beer commercial with a beautiful model, it would be really important to know whether the average twenty-two-year-old male in your target audience fixates only on the model or eventually moves to your can of beer. Sesame Street went to Harvard in 1975 for the same reason. When kids watched "Oscar's Blending" or "Hug," were they watching and learning about the words, or were they simply watching the Muppets?

The experiment was conducted with twenty-one four and five-year-olds, who were brought to the Harvard School of Education over the course of a week by their parents. One by one they were seated in an antique barber's chair with a padded headrest about three feet away from a 17-inch color television monitor. A Gulf amp;Western infrared Eye View Monitor was set up just off to the left, carefully calibrated to track the fovea movements of each subject. What they found was that "Hug" was a resounding success. Seventy-six percent of all fixations were on the letters. Better still, 83 percent of all preschoolers fixated on the letters in a left-to-right sequence — mimicking, in other words, the actual reading process. "Oscar's Blending," on the other hand, was a disaster. Only 35 percent of total fixations fell on the letters. And exactly zero percent of the preschoolers read the letters from left to right. What was the problem? First, the letter shouldn't have been on the bottom of the screen because, as almost all eye movement research demonstrates, when it comes to television people tend to fixate on the center of the screen. That issue, though, is really secondary to the simple fact that the kids weren't watching the letters because they were watching Oscar. They were watching the model and not the beer can. "I remember 'Oscar's Blending,'" Flagg says. "Oscar was very active. He was really making a fuss in the background, and the word is not close to him at all. He's moving his mouth a lot, moving his hands. He has things in his hands. There is a great deal of distraction. The kids don't focus on the letters at all because Oscar is so interesting." Oscar was sticky. The lesson wasn't.

This was the legacy of Sesame Street: If you paid careful attention to the structure and format of your material, you could dramatically enhance stickiness. But is it possible to make a show even stickier than Sesame Street? This was what three young television producers at the Nickelodeon Network in Manhattan asked themselves in the mid-1990s. It was a reasonable question. Sesame Street, after all, was a product of the 1960s, and in the intervening three decades major strides had been made in understanding how children's minds work. One of the Nickelodeon producers, Todd Kessler, had actually worked on SesameStreet and left the show dissatisfied. He didn't like the fast-paced "magazine" format of the show. "I love SesameStreet," he says. "But I always believed that kids didn't have short attention spans that they could easily sit still for a half an hour." He found traditional children's television too static. "Because the audience is not all that verbal or even preverbal, it is important to tell the story visually," he went on. "It's a visual medium, and to make it sink in, to make it powerful, you've got to make use of that. There is so much children's television that is all talk. The audience has a hard time keeping up with that." Kessler's colleague, Tracy Santomero, grew up on Sesame Street and had similar misgivings. "We wanted to learn from SesameStreet and take it one step further," Santomero said. "TV is a great medium for education. But people up until now haven't explored the potential of it. They've been using it in a rote way. I believed we could turn that around."

What they came up with is a show called Blue's Clues. It is half an hour, not an hour. It doesn't have an ensemble cast. It has just one live actor, Steve, a fresh-faced man in his early twenties in khakis and a rugby shirt who acts as the show's host. Instead of a varied, magazine formal, each episode follows a single story line — the exploits of an animated dog by the name of Blue. It has a flat, two-dimensional feel, more like a video version of a picture book than a television show. The pace is deliberate. The script is punctuated with excruciatingly long pauses. There is none of the humor or wordplay or cleverness that characterizes Sesame Street. One of the animated characters on the show, a mailbox, is called Mailbox. Two other regular characters, a shovel and a pail, are called Shovel and Pail. And Blue, of course, the show's star, is Blue because he's the color blue. It is difficult, as an adult, to watch Blue's Clues and not wonder how this show could ever represent an improvement over Sesame Street. And yet it does. Within months of its debut in 1996, Blue'sClues was trouncing Sesame Street in the ratings. On the Distracter test, it scores higher than its rival in capturing children's attention. Jennings Bryant, an educational researcher at the University of Alabama, conducted a study of 120 children, comparing the performance of regular Blue's Clues watchers to watchers of other educational shows on a series of cognitive tests.

"After six months we began to get very big differences," Bryant said. "By almost all of our measures of flexible thinking and problem solving, we had statistically significant differences. If there were sixty items on the test, you might find that the Blue's Clues watchers were correctly identifying fifty of them, and the control group was identifying thirty-five." Blue's Clues may be one of the stickiest television shows ever made.

How is it that such an unprepossessing show is even stickier than Sesame Street? The answer is that SesameStreet, as good as it is, has a number of subtle but not insignificant limitations. Consider, for example, the problem created by the show's insistence on being clever. From the beginning Sesame Street was intended to appeal to both children and adults. The idea was that one of the big obstacles facing children — particularly children from lower-income families — were that their parents didn't encourage or participate in their education. Sesame Street's creators wanted a show that mothers would watch along with their children. That's why the show is loaded with so many "adult" elements, the constant punning and pop culture references like Monsterpiece Theater or the Samuel Beckett parody "Waiting for Elmo." (The show's head writer, Lou Berger, says that the reason he applied for a job at SesameStreet was because of a Kermit sketch he saw while watching the show with his son in 1979. "It was one of those crazy fairy tales. They were looking for a princess in distress. Kermit ran out to this female Muppet princess and said" — and here Berger did a pitch-perfect Kermit — "'Excuse me, are you a female princess in distress?' And she said, 'What does this look like? A pant suit?' I remember thinking, 'That's so great. I have to work there.'")

The problem is, preschoolers don't get these kinds of jokes, and the presence of the humor — like the elaborate pun on "distress" — can serve as a distraction. There is a good example of this in an episode of Sesame Street called "Roy" that ran on Christmas Eve in 1997. The episode opens with Big Bird running into a mail carrier, who has never been on Sesame Street before. The mail carrier hands Big Bird a package, and Big Bird is immediately puzzled: "If this is the first time you have ever been here," he asks, "how did you know I was Big Bird?"

MAIL CARRIER: Well, you have to admit, it's easy to figure out! [Gestures broadly at Big Bird]

BB: It is? [Looks at himself]. Oh, I see. The package is for Big Bird, and I'm a big bird. I forget sometimes. I'm just what my name says. Big Bird is a big bird.

Big Bird becomes sad. He realizes that everyone else has a name — like Oscar, or Snuffy — but he has only a description. He asks the mail carrier what her name is. She says Imogene.

BB: Gee, that's a nice name. [Looking to the camera, wistfully] I wish I had a real name like that, instead of one that just says what I am, as if I were an apple or a chair or something."

Thereupon begins a search by Big Bird for a new name. With the help of Snuffy, he canvases Sesame Street for suggestions — Zackledackle, Butch, Bill, Omar, Larry, Sammy, Ebenezer, Jim, Napoleon, Lancelot, Rocky — before settling on Roy. But then, once everyone starts calling him by his new name. Big Bird realizes that he doesn't like it after all. "Somehow it doesn't seem right," he says. "I think I made a big mistake." He switches back. "Even if Big Bird isn't a regular name," he concludes, "it's my name, and I like the way all my friends say it."

This was, at least on the surface, an excellent episode. The premise is challenging and conceptual, but fascinating. It deals candidly with emotion, and, unlike other children's shows, tells children that it's okay not to be happy all of the time. Most of all, it's funny.

It sounds like it should be a winner, right?

Wrong. The Roy show was tested by the Sesame Street research staff and the numbers were very disappointing. The first segment involving Snuffy and Big Bird did well. As you would expect, the viewers were curious. Then things began to fall apart. By the second of the street scenes, attention dropped to 80 percent. By the third, 78 percent. By the fourth 40 percent, then 50, then 20. Alter viewing the show, the kids were quizzed on what they had seen. "We asked very specific questions and were looking for clear answers," Rosemary Truglio, SesameStreet's research head said. "What was the show about? Sixty percent knew. What did Big Bird want to do? Fifty three percent knew. What was Big Bird's new name? Twenty percent knew. How did Big Bird feel at the end? Fifty percent knew." By comparison, another of the shows tested by Sesame Street at the very same time recorded 90 percent plus correct answers on the postshow quiz. The show simply wasn't making any impression. It wasn't sticking.

Why did the show fail? The problem, at root, is with the premise of the show — the essential joke that Big Bird doesn't want to be known as a big bird. That's the kind of wordplay that a preschooler simply doesn't understand. Preschoolers make a number of assumptions about words and their meaning as they acquire language, one of the most important of which is what the psychologist Ellen Markman calls the principle of mutual exclusivity. Simply put, this means that small children have difficulty believing that any one object can have two different names. The natural assumption of children, Markman argues, is that if an object or person is given a second label, then that label must refer to some secondary property or attribute of that object. You can see how useful this assumption is to a child faced with the extraordinary task of assigning a word to everything in the world. A child who learns the word elephant knows, with absolute certainty, that it is something different from a dog. Each new word makes the child's knowledge or the world more precise. Without mutual exclusivity, by contrast, if a child thought that elephant could simply be another label for dog, then each new word would make the world seem more complicated. Mutual exclusivity also helps the child think clearly. "Suppose," Markman writes, "a child who already knows 'apple' and 'red' hears someone refer to an apple as 'round.' By mutual exclusivity, the child can eliminate the object (apple) and its color (red) as the meaning of 'round' and can try to analyze the object for some other property to label."

What this means, though, is that children are going to have trouble with objects that have two names, or objects that change names. A child has difficulty with, say, the idea that an oak is both an oak and a tree; he or she may well assume that in that case "tree" is a word for collection of oaks.

The idea, then, that Big Bird no longer wants to be called Big Bird but instead wants to be called Roy is almost guaranteed to befuddle a preschooler. How can someone with one name decide to have another name? Big Bird is saying that Big Bird is merely a descriptive name of the type of animal he is, and that he wants a particular name. He doesn't want to be a tree. He wants to be an oak. But three- and four-year-olds don't understand that a tree can also be an oak. To the extent that they understand what is going on at all, they probably think that Big Bird is trying to change into something else — into some other kind of animal, or some other collection of animals. And how could he do that?

There's a deeper problem. Sesame Street is a magazine show. A typical show consists of at least forty distinct segments, none more than about three minutes — street scenes with the actors and Muppets, animation, and short films from outside the studio. With shows like "Roy," in the late 1990s, the writers of the show attempted, for the first time, to link some of these pieces together with a common theme. For most of the show's history, though, the segments were entirely autonomous; in fact new Sesame shows were constructed, for the most part, by mixing together fresh street scenes with animated bits and filmed sequences from the show's archives.

The show's creators had a reason for wanting to construct Sesame Street this way. They thought preschoolers did not have the attention span to handle anything other than very short, tightly focused segments. "We looked at the viewing patterns of young children, and we found that they were watching Laugh-In," says Lloyd Morrisett, who was one of the show's founders. "That had a very strong effect on the early Sesame Street. Zany, relatively quick one-liners. The kids seemed to love it." SesameStreet's creators were impressed even more by the power of television commercials. The sixties were the golden age of Madison Avenue, and at the time it seemed to make perfect sense that if a 60-second television spot could sell breakfast cereal to a four-year-old, then it could also sell that child the alphabet. Part of the appeal of Jim Henson and the Muppets to the show's creators, in fact, was that in the 1960s Henson had been running a highly successful advertising shop. Many of the most famous Muppets were created for ad campaigns: Big Bird is really a variation of a seven-foot dragon created by Henson for La Choy commercials; Cookie Monster was a pitchman for Frito-Lay; Grover was used in promotional films for IBM. (Henson's Muppet commercials from the 50s and 60s are hysterically funny but have a dark and edgy quality that understandably was absent from his SesameStreet work.)

"I think the most significant format feature in a commercial is that it's about one thing," said Sam Gibbon, one of the earliest Sesame Street producers. "It's about selling one idea. The notion of breaking down the production of Sesame Street into units small enough so they could address a single educational goal like an individual letter owed a lot to that technique of commercials."

But is the commercial theory of learning true? Daniel Anderson says that new research suggests that children actually don't like commercials as much as we thought they did because commercials "don't tell stories, and stories have a particular salience and importance to young people." The original Sesame Street was anti-narrative: it was, by design, an unconnected collection of sketches. "It wasn't just the ads that influenced the early SesameStreet," Anderson says. "There was also a theoretical perspective at the time, based in part on [the influential child psychologist] Piaget, that a preschool child couldn't follow an extended narrative." Since the late 1960s, however, this idea has been turned on its head. At three and four and five, children may not be able to follow complicated plots and subplots. But the narrative form, psychologists now believe, is absolutely central to them. "It's the only way they have of organizing the world, of organizing experience," Jerome Bruner, a psychologist at New York University, says. "They are not able to bring theories that organize things in terms of cause and effect and relationships, so they turn things into stories, and when they try to make sense of their life they use the storied version of their experience as the basis for further reflection. If they don't catch something in a narrative structure, it doesn't get remembered very well, and it doesn't seem to be accessible for further kinds of mulling over."

Bruner was involved, in the early 1980s, in a fascinating project — called "Narratives from the Crib" — that was critical in changing the views of many child experts. The project centered on a two-year-old girl from New Haven called Emily, whose parents — both university professors — began to notice that before their daughter went to sleep at night she talked to herself. Curious, they put a small microcassette recorder in her crib and, several nights a week, for the next fifteen months, recorded both the conversations they had with Emily as they put her to bed and the conversations she had with herself before she fell asleep. The transcripts — 122 in all — were then analyzed by a group of linguists and psychologists led by Katherine Nelson of Harvard University. What they found was that Emily's conversations with herself were more advanced than her conversations with her parents. In fact, they were significantly more advanced. One member of the team that met to discuss the Emily tapes, Carol Fleisher Feldman, later wrote:

In general, her speech to herself is so much richer and more complex [than her speech to adults] that it has made all of us, as students of language development, begin to wonder whether the picture of language acquisition offered in the literature to date does not underrepresent the actual patterns of the linguistic knowledge of the young child. For once the lights are out and her parents leave the room, Emily reveals a stunning mastery of language forms we would never have suspected from her [everyday] speech.

Feldman was referring to things like vocabulary and grammar and — most important — the structure of Emily's monologues. She was making up stories, narratives that explained and organized the things that happened to her. Sometimes these stories were what linguists call temporal narratives. She would create a story to try to integrate events, actions, and feelings into one structure — a process that is a critical part of a child's mental development. Here is a story Emily told herself at 32 months, which I will quote at length to emphasize just how sophisticated children's speech is when they are by themselves:

Tomorrow when we wake up from bed, first me and Daddy and Mommy, you, eat breakfast eat breakfast like we usually do, and then we're going to play and then soon as Daddy comes, Carl's going to come over, and then we're going to play a little while. And then Carl and Emily are both going down the car with somebody, and we're going to ride to nursery school [whispered], and then when we get there, we're all going to get out of the car, go into nursery school, and Daddy's going to give us kisses, then go, and then say, and then we will say goodbye, then he's going to work and we're going to play at nursery school. Won't that be funny? Because sometimes I go to nursery school cause it's a nursery school day. Sometimes I stay with Tanta all week. And sometimes we play mom and dad. But usually, sometimes, I, um, oh go to nursery school. But today I'm going to nursery school in the morning. In the morning, Daddy in the, when and usual, we're going to eat breakfast like we usually do, and then we're going to… and then we're going to… play. And then we're, then the doorbell's going to ring, and here comes Carl in here, and then Carl, and then we are all going to play, and then…

Emily is describing her Friday routine. But it's not a particular Friday. It's what she considers an ideal Friday, a hypothetical Friday in which everything she wants to happen happens. It is, as Bruner and Joan Lucariello write in their commentary on the segment,

a remarkable act of world making… she uses tonal emphasis, prolongation of key words, and a kind of "reenactment'' reminiscent of the we-are-there cinema verite (with her friend Carl practically narrated through the door as he enters). As if to emphasize that she has everything "down pat" she delivers the monologue in a rhythmic, almost singsong way. And in the course of the soliloquy, she even feels free to comment on the drollness of the course that events are taking ("Won't that be funny").

It is hard to look at this evidence of the importance of narrative and not marvel at the success of Sesame Street. Here was a show that eschewed what turns out to be the most important of all ways of reaching young children. It also diluted its appeal to preschoolers with jokes aimed only at adults. Yet it succeeded anyway. That was the genius of Sesame Street, that through the brilliance of its writing and the warmth and charisma of the Muppets it managed to overcome what might otherwise have been overwhelming obstacles. But it becomes easy to understand how you would make a children's show even stickier than SesameStreet. You'd make it perfectly literal, without any wordplay or comedy that would confuse preschoolers. And you'd teach kids how to think in the same way that kids teach themselves how to think — in the form of the Story. You would make, in other words, Blue's Clues.

Every episode of Blue's Clues is constructed the same way. Steve, the host, presents the audience with a puzzle involving Blue, the animated dog. In one show the challenge is to figure out Blue's favorite story. In another, it is to figure out Blue's favorite food. To help the audience unlock the puzzle. Blue leaves behind a series of clues, which are objects tattooed with one of his paw prints. In between the discovery of the clues, Steve plays a series of games — mini-puzzles — with the audience that are thematically related to the overall puzzle. In the show about Blue's favorite story, for example, one of the mini-puzzles involves Steve and Blue silting down with the Three Bears, whose bowls of porridge have been mixed up, and enlisting the audience's help in matching the small, middle, and large bowls with Mama, Papa, and Baby Bear. As the show unfolds, Steve and Blue move from one animated set to another, from a living room to a garden to fantastical places, jumping through magical doorways, leading viewers on a journey of discovery, until, at the end of the story, Steve returns to the living room. There, at the climax of every show, he sits down in a comfortable chair to think — a chair known, of course, in the literal world of Blue'sClues, as the Thinking Chair. He puzzles over Blue's three clues and attempts to come up with the answer.

This much is, obviously, a radical departure from Sesame Street. But having turned their back on that part of the Sesame Street legacy, the creators of Blue's Clues then went back and borrowed those parts of Sesame Street that they thought did work. In fact, they did more than borrow. They took those sticky elements and tried to make them even stickier. The first was the idea that the more kids are engaged in watching something — intellectually and physically — the more memorable and meaningful it becomes. "I'd noticed that some segments on Sesame Street elicited a lot of interaction from kids, where the segments asked for it," says Daniel Anderson, who worked with Nickelodeon in designing Blue's Clues. "Something that stuck in my mind was when Kermit would hold his finger to the screen and draw an animated letter, you'd see kids holding their fingers up and drawing a letter along with him. Or occasionally, when a Sesame Street character would ask a question, you'd hear kids answer out loud. But Sesame Street just somehow never took that idea and ran with it. They knew that kids did this some of the time, but they never tried to build a show around that idea. Nickelodeon did some pilot shows before Blue's Clues where kids would be explicitly asked to participate, and lo and behold, there was a lot of evidence that they would. So putting these ideas together, that kids are interested in being intellectually active when they watch TV, and given the opportunity they'll be behaviorally active, that created the philosophy for Blue's Clues."

Steve, as a result, spends almost all his time on screen talking directly at the camera. When he enlists the audience's help, he actually enlists the audience's help. Often, there are close-ups of his face, so it is as if he is almost in the room with his audience. Whenever he asks a question, he pauses. But it's not a normal pause. It's a preschooler's pause, several beats longer than any adult would ever wait for an answer. Eventually an unseen studio audience yells out a response. But the child at home is given the opportunity to shout out an answer of his own. Sometimes Steve will play dumb. He won't be able to find a certain clue that might be obvious to the audience at home and he'll look beseechingly at the camera. The idea is the same: to get the children watching to verbally participate, to become actively involved. If you watch Blue's Clues with a group of children, the success of this strategy is obvious. It's as if they're a group of diehard Yankees fans at a baseball game.

The second thing that Blue's Clues took from SesameStreet was the idea of repetition. This was something that had fascinated the CTW pioneers. In the five pilot shows that Palmer and Lesser took to Philadelphia in 1969, there was a one-minute bit called Wanda the Witch that used the w sound over and over: Wanda the Witch wore a wig in the windy winter in Washington, etc., etc. "We didn't know how much we could repeat elements," Lesser says.

"We put it in three times on the Monday, three times on the Tuesday, three times on the Wednesday, left it out on Thursday, then put it in right at the end of the Friday show. Some of the kids toward the end of the day Wednesday were saying, not Wanda the Witch again. When Wanda the Witch came back Friday, they jumped and clapped. Kids reach a saturation point. But then nostalgia sets in."

Not long afterward (and quite by accident), the Sesame Street writers figured out why kids like repetition so much. The segment in question this time featured the actor James Earl Jones reciting the alphabet. As originally taped, Jones took long pauses between letters, because the idea was to insert other elements between the letters. But Jones, as you can imagine, cut such a compelling figure that the Sesame Street producers left the film as it was and played it over and over again for years: the letter A or B, etc., would appear on the screen, there would be a long pause, and then Jones would boom out the name and the letter would disappear. "What we noticed was that the first time through, kids would shout out the name of the letter after Jones did," Sam Gibbon says. "After a couple of repetitions, they would respond to the appearance of the letter before he did, in the long pause. Then, with enough repetitions, they would anticipate the letter before it appeared. They were sequencing themselves through the piece; first they learned the name of the letter, then they learned to associate the name of the letter with its appearance, then they learned the sequence of letters." An adult considers constant repetition boring, because it requires reliving the same experience over and again. But to preschoolers repetition isn't boring, because each time they watch something they are experiencing it in a completely different way. At CTW, the idea of learning through repetition was called the James Earl Jones effect.

Blue's Clues is essentially a show built around the James Earl Jones effect. Instead of running new episodes one alter another, and then repeating them as reruns later in the seasons — like every other television show — Nickelodeon runs the same Blue's Clues episode for five straight days, Monday through Friday, before going on to the next one. As you can imagine, this wasn't an idea that came easily to Nickelodeon. Santomero and Anderson had to convince them. (It also helped that Nickelodeon didn't have the money to produce a full season of Blue'sClues shows.) "I had the pilot in my house, and at the time my daughter was three and a half and she kept watching it over and over again," Anderson says. "I kept track. She watched it fourteen times without any lagging of enthusiasm." When the pilot was taken out into the field for testing, the same thing happened. They showed it five days in a row to a large group of preschoolers, and attention and comprehension actually increased over the course of the week — with the exception of the oldest children, the five-year-olds, whose attention fell off at the very end. Like the kids watching James Earl Jones, the children responded to the show in a different way with each repeat viewing, becoming more animated and answering more of Steve's questions earlier and earlier. "If you think about the world of a preschooler, they are surrounded by stuff they don't understand — things that are novel. So the driving force for a preschooler is not a search for novelty, like it is with older kids, it's a search for understanding and predictability," says Anderson. "For younger kids, repetition is really valuable. They demand it, When they see a show over and over again, they not only are understanding it better, which is a form of power, but just by predicting what is going to happen, I think they feel a real sense of affirmation and self-worth. And Blue's Clues doubles that feeling, because they also feel like they are participating in something. They feel like they are helping Steve."

Of course, kids don't always like repetition. Whatever they are watching has to be complex enough to allow, upon repeated exposure, for deeper and deeper levels of comprehension. At the same time, it can't be so complex that the first time around it baffles the children and turns them off. In order to strike this balance, Blue's Clues engages in much of the same kind of research as SesameStreet — but at a far more intense level. Where SesameStreet tests a given show only once — and after it's completed — Blue's Clues tests shows three times before they go on the air. And while Sesame Street will typically only test a third of its episodes. Blue's Clues tests them all.

I accompanied the Blue's Clues research team on one of their weekly excursions to talk to preschoolers. They were led by Alice Wilder, director of research for the show, a lively dark-haired woman who had just finished her doctorate in education at Columbia University. With her were two others, both women in their early twenties — Alison Oilman and Allison Sherman. On the morning that I joined them they were testing a proposed script at a preschool in Greenwich Village.

The script being tested was about animal behavior. It was, essentially, a first draft, laid out in a picture book that roughly corresponded to the way the actual episode would unfold, scene by scene, on television. The Blue'sClues tester played the part of Steve, and walked the kids through the script, making a careful note of all the questions they answered correctly and those that seemed to baffle them. At one point, for example, Sherman sat down with a towheaded five-year-old named Walker and a four-and-a-half-year-old named Anna in a purple-and-white checked skirt. She began reading from the script. Blue had a favorite animal. Would they help us find out what it was? The kids were watching her closely. She began going through some of the subsidiary puzzles, one by one. She showed them a picture of an anteater.

"What does an anteater eat?" she asked.

Walker said, "Ants."

Sherman turned the page to a picture of an elephant. She pointed at its trunk.

"What's that?"

Walker peered in. "A trunk."

She pointed at the tusks. "Do you know what the white things are?"

Walker looked again. "Nostrils."

She showed them a picture of a bear, then came the first Blue's clue, a little splotch of white and black tattooed with one of Blue's paw prints.

"That's black and white," Anna said.

Sherman looked at the two of them. "What animal could Blue want to learn about?" She paused. Anna and Walker looked puzzled. Finally Walker broke the silence: "We had better go to the next clue."

The second round of puzzles was a little harder. There was a picture of a bird. The kids were asked what the bird was doing — the answer was singing — and then why it was doing that. They talked about beavers and worms and then came to the second Blue's clue — an iceberg. Anna and Walker were still stumped. On they went to the third round, a long discussion of fish. Sherman showed them a picture of a little fish lying camouflaged at the bottom of the sea, eying a big fish.

"Why is the fish hiding?" Sherman asked.

WALKER: "Because of the giant fish."

ANNA: "Because he will eat him."

They came to the third Blue's clue. It was a cardboard cutout of one of Blue's paw prints. Sherman took the paw print and moved it toward Walker and Anna, wiggling it as she did.

"What's this doing?" she asked.

Walker screwed up his face in concentration. "It's walking like a human," he said.

"Is it wriggling like a human?" Sherman asked.

"It's waddling," Anna said.

Sherman went over the clues in order: black and white, ice, waddling.

There was a pause. Suddenly Walker's face lit up. "It's a penguin!" He was shouting with the joy of discovery. "A penguin's black and white. It lives on the ice and it waddles!"

Blue's Clues succeeds as a story of discovery only if the clues are in proper order. The show has to start out easy — to give the viewers confidence — and then get progressively harder and harder, challenging the preschoolers more and more, drawing them into the narrative. The first set of puzzles about anteaters and elephants had to be easier than the set of puzzles about beavers and worms, which in turn had to be easier than the final set about fish. The layering of the show is what makes it possible for a child to watch the show four and five times: on each successive watching they master more and more, guessing correctly deeper into the program, until, by the end, they can anticipate every answer.

After the morning of testing, the Blue's Clues team sat down and went through the results of the puzzles, one by one. Thirteen out of the 26 children guessed correctly that anteaters ate ants, which wasn't a good response rate for the first clue. "We like to open strong," Wilder said. They continued on, rustling through their papers. The results of a puzzle about beavers drew a frown from Wilder. When shown a picture of a beaver dam, the kids did badly on answering the first question — what is the beaver doing? — but very well (19 out of 26) on the second question, why is he doing it? "The layers are switched," Wilder said. She wanted the easier question first. On to the fish questions: Why was the little fish hiding from the big fish? Sherman looked up from her notes. "I had a great answer. 'The little fish didn't want to scare the big fish.' That's why he was hiding." They all laughed.

Finally, came the most important question. Was the order of Blue's clues correct? Wilder and Oilman had presented the clues in the order that the script had stipulated: ice, waddle, then black and white. Four of the 17 kids they talked to guessed penguin after the first clue, six more guessed it after the second clue and four alter all three clues. Wilder then turned to Sherman, who had given her clues in a different order: black and white, ice, waddle.

"I had no correct answers out of nine kids alter one clue," she reported. "After ice, I was one of nine, and after waddle I was six of nine."

"Your clincher clue was waddle? That seems to work,"

Wilder responded. "But along the way were they guessing lots of different things?"

"Oh yes," Sherman said. "After one clue, I had guesses of dogs, cows, panda bears, and tigers. After ice, I got polar bears and cougars."

Wilder nodded. Sherman's clue order got the kids thinking as broadly as possible early in the show, but still preserved the suspense of penguin until the end. The clue order they had — the clue order that seemed the best back when they were writing the script — gave the answer away far too soon. Sherman's clue order had suspense. The original order did not. They had spent a morning with a group of kids and come away with just what they wanted. It was only a small change. But a small change is often all that it takes.

There is something profoundly counterintuitive in the definition of stickiness that emerges from all these examples. Wunderman stayed away from prime-time slots for his commercials and bought fringe time, which goes against every principle of advertising. He eschewed slick "creative" messages for a seemingly cheesy "Gold Box" treasure hunt. Levanthal found that the hard sell — that trying to scare students into getting tetanus shots — didn't work, and what really worked was giving them a map they didn't need directing them to a clinic that they already knew existed. Blue's Clues got rid of the cleverness and originality that made Sesame Street the most beloved television program of its generation, created a plodding, literal show, and repeated each episode five times in a row.

We all want to believe that the key to making an impact on someone lies with the inherent quality of the ideas we present. But in none of these cases did anyone substantially alter the content of what they were saying. Instead, they tipped the message by tinkering, on the margin, with the presentation of their ideas, by putting the Muppet behind the H-U-G, by mixing Big Bird with the adults, by repeating episodes and skits more than once, by having Steve pause just a second longer than normal after he asks a question, by putting a tiny gold box in the corner of the ad. The line between hostility and acceptance, in other words, between an epidemic that tips and one that does not, is sometimes a lot narrower than it seems. The creators of Sesame Street did not junk their entire show after the Philadelphia disaster. They just added Big Bird, and he made all the difference in the world. Howard Levanthal didn't redouble his efforts to terrify his students into getting a tetanus shot. He just threw in a map and a set of appointment times. The Law of the Few says that there are exceptional people out there who are capable of starting epidemics. All you have to do is find them. The lesson of stickiness is the same. There is a simple way to package information that, under the right circumstances, can make it irresistible. All you have to do is find it.