Stanley Greenspan's parenting prescription seems straightforward enough: Spend at least 30 minutes a day on your kids' level, letting them call the shots. But like all expert child-rearing advice, 'floor time' isn't as simple as it sounds.

A weekday afternoon, after school. I'm sitting on the floor with my 5-year-old daughter, who is busy removing toy furniture and rotund plastic figures from the interior of her dollhouse. I watch her expectantly: I am ready to begin a new chapter in my development as a parent.

Like many parents these days, I don't just rely on my instincts; keenly feeling my lack of preparation for what I consider the most important job of my life, I look to experts. And lately, the expert whose ideas have impressed me the most is Stanley Greenspan. An internationally renowned child psychiatrist, the author of four books for parents and 16 for professionals, Greenspan -- who just happens to live five minutes away from me in Bethesda -- seems to have spoken to every local parents' group worth its salt. I've read him, I've heard him, and I think I've got his basic message straight.

At first it seems ridiculously simple: Spend time with your child. But Greenspan is talking about something beyond "quality time" -- whatever that means. He's also talking about something beyond the kind of "quantity time" the current generation of parents might have gotten when they were kids, working with Dad on his Saturday building project or helping Mom make dinner.

What Greenspan is saying is this: Spend at least 30 minutes a day focusing exclusively on your child, and let her take the lead. Tune in to her interests and feelings, and march to her drummer. If she wants you to get down on all fours and bark like a dog, do it. Participate in the action, but don't control it -- she's the director, and you're the assistant director. By meeting her at her level and entering her world through pretend play -- engaging in what Greenspan calls "floor time" -- you will be fostering a warm, empathetic relationship that will promote your child's healthy emotional and cognitive growth. By putting her in charge, you'll be giving her the freedom to explore what's important to her -- and the message that what's important to her is also important to you. Floor time, writes Greenspan, "creates the whole basis for security, trust, and self-worth that a child will need from here on."

It's not that I've never played with my two children. I've built my share of Duplo towers, I've "talked" for the baby elephant or the mommy hippo. But before this, I've only done it when my kids have demanded it -- and even then, part of me has been elsewhere, running through my mental list of Things to Do. As my kids have grown older and more self-sufficient, they've stopped asking me to play. And I've seen this as a breakthrough -- not to mention a chance for me to have a little more time for myself.

But at the same time I've been vaguely concerned that the warmer aspects of my relationship with my kids have been eroding as they've needed me less. And reading Greenspan has made me reassess. I spend lots of time with my kids (I work part time), but how much of it qualifies as "floor time"? For the most part, I'm there in the background, available to bring them snacks, help them find a lost toy -- or, all too often, enforce some rule. How much time do I spend letting them set the agenda? How much time do they spend sharing their thoughts and feelings with me?

So here I am, on the floor with my daughter, eager to play.

Once Sophie gets over her initial shock -- the stage where she looks at me as though to say, you mean you actually want to play with me? -- she is thrilled. So far, our interaction could have been drawn straight from one of the case histories in Greenspan's books: Sophie is assigning roles for the drama that she is about to unfold.

"You be all the grown-ups and the boy," she tells me. "I'll be all the girl children."

Now we each have a row of characters lined up before us on the floor, facing each other. I await further direction. After a few seconds of silence, Sophie looks at me impatiently.

"Well?" she demands. "Go ahead -- play!"

Later, I approach my 7-year-old son, who is absorbed in some pretend play of his own. It appears to involve a violent clash between two groups of action figures. I hover nearby, waiting for my opening, prepared to take on the role of the bad guys, the good guys -- whatever he wants. At first Sam ignores me, but after a minute or two his play slows to a halt.

"Mommy," he says politely, looking up at me, "could you please go someplace else?" ANY PARENT who has read a parenting book and tried to put its advice into practice knows that it's usually not as simple as it sounds. You try using your half of the suggested dialogue, but sometimes it seems as though your kids just haven't read the script. And Greenspan's approach, once you look at it carefully, doesn't even sound that simple.

What he's done, drawing on years of clinical practice and research, is to map out a course of normal emotional development -- an ambitious attempt to integrate two fundamental theories of developmental stages: that of Freud, who focused on the child's psychosexual drives and the feelings they engender, and that of Piaget, who focused on cognition. For Greenspan, these two aspects of development -- the emotional and the cognitive -- are inseparable. All learning and all creative thinking, he says, stem from a child's emotional experience of relationships.

By way of illustrating this point, Greenspan likes to offer the example of two groups of children who were asked what they thought about bosses. One group simply listed different kinds of bosses: police officers, teachers, parents. The second group's answers were along the following lines: Well, sometimes I don't like bosses, like when my parents say I have to go to sleep and I don't want to. But sometimes I need a boss, like if I'm hitting my brother and my parents tell me to stop. So I guess there are good bosses and bad bosses.

Which group, Greenspan asks his audiences, has the better abstract reasoning ability?

The second, the audience agrees. And why? Because, Greenspan says, these children were "abstracting off" their own personal experience: They first looked to their emotional reaction to bosses and then analyzed that reaction and put it into a logical framework. Children in the first group were unable to draw on emotional experience -- either because they had been deprived of it, or because they had serious physiological problems that prevented them from taking it in.

"Without the emotional reaction," Greenspan says, "you get rote thinking, like a computer."

The parent's role, then, is to provide the interaction and emotional experiences that fuel development. But in order to do that, the parent has to know where the child is on Greenspan's map of developmental stages. "If you don't meet the child at the stage he's at," Greenspan says, "you won't be relating."

In Greenspan's first two books for parents, First Feelings (1985) and The Essential Partnership (1989), he identified certain emotional milestones that children usually reach during the years from birth to age 4 or 5. A baby's first emotional challenge, Greenspan says, is simply to calm down and pay attention. Then, at about 4 to 6 months, babies begin the crucial process of learning to relate to others. First they coo and smile and "fall in love" with their parents, then they begin to send out and understand nonverbal cues like smiles and frowns. Later on, they organize those gestures into purposeful communication -- like the hungry toddler who takes his mother to the refrigerator and bangs on the door.

During the next stage children form ideas about their emotions -- saying "I'm angry" instead of simply kicking or hitting, for example. At 2 or 3, children begin to connect these emotional ideas into what Greenspan calls emotional thinking: "I'm angry today because you didn't play with me." Their play becomes less random, and they begin to develop plots. The recognition of cause and effect that occurs at this stage, according to Greenspan, underlies all abstract thinking.

In his third book for parents, Playground Politics (1993), Greenspan expanded his developmental "road map" to the grade-school years. From about ages 4 to 7 -- a stage Greenspan calls "The World Is My Oyster" -- children develop a rich sense of fantasy that can lead both to feelings of omnipotence ("I'm a Power Ranger!") and to overwhelming fears ("There are monsters under the bed!"). At the same time, children are learning to negotiate triangular relationships: Instead of focusing exclusively on Mommy or Daddy, they start to play one parent off against the other. This stage is followed by "The World Is Other Kids," when the peer group is paramount. Through both of these stages, the child is figuring out how to deal with competition and rivalry. If all goes well, by about age 10 the child will be in the stage of "The World Inside Me," when feelings of competition begin to give way to internalized standards that stem from a secure self-image.

But parents can't just look to their child's age to locate his developmental level, because not everyone masters each emotional stage at the same time. A 5-year-old, for example, might be getting into trouble at school because he never fully mastered the stage that most children reach by 18 months: learning to read nonverbal cues. If he's acting up in class and the teacher gives him an exasperated look, he might misinterpret her expression as one of amusement and keep right on misbehaving. And, Greenspan says, "80 percent of kids who have problems with their peers can't read nonverbal cues."

So -- anxious parents want to know -- what determines whether a child smoothly negotiates these stages of development? Much depends, says Greenspan, on the child's unique "sensory profile" -- how he reacts to external stimuli like sound, light or touch. This is a topic that is explored in detail in Greenspan's most recent book for parents, The Challenging Child (1995). Some babies and children find a light, feathery touch pleasurable; for others it feels like sandpaper being rubbed over sunburned skin. Some kids have more trouble than others making sense of what they hear: A series of instructions ("Go to your room, find your jacket, put it on, and come downstairs") can sound like gobbledygook.

These different sensitivities obviously have consequences for behavior and personality. A child who is highly sensitive to sensory stimuli can easily feel overwhelmed and fall apart. A child who is underreactive might withdraw into himself; at the far end of the spectrum, he might be diagnosed as autistic.

The anxious parent is now thinking: If my child is born with these characteristics, or acquires them very early in life (the causes for these variations in sensitivity are not yet clear), why bother with parenting books? How much influence can I really have?

A lot, says Greenspan. "The parenting may not be the reason the child is having problems," he says, "but it may be part of the solution."

In the nature-nurture debate, Greenspan is squarely in both camps: Nature may determine what you've got to work with, but you -- the parent -- can do a lot of work. Some of it may be easy. If your baby is sensitive to high-pitched sounds and therefore cries when you coo at her in the traditional "mommy" voice, you can simply lower your pitch. Some of it is hard. If your school-age child is so underreactive that he's withdrawn into himself, you might need to embark on a whole program of "wooing" him. You'll need to radiate enough energy and enthusiasm for two, remain unfazed by tantrums, engage in the kind of rough physical play that an underreactive child often enjoys -- while at the same time encouraging your child to show his own initiative. This is the kind of work you do during floor time.

Not all children present such problems, of course. And even when they do, not all parents have the decidedly upper-middle-class luxury of obsessing over them. Still, Greenspan recommends floor time -- half an hour a day, every day -- for all children, and all parents. With older children, floor time might not actually be on the floor, and it probably won't involve pretend play. You might build with Legos, sort baseball cards, or just engage in chitchat -- whatever the child wants to do. Eventually, goes the theory, the older child will share with you his thoughts and feelings -- just as a younger child does, more indirectly, in pretend play -- and you will help him master the crucial skill of reflecting on and analyzing his emotions.

While floor time is at the core of Greenspan's program, there's more to it as well. During "problem-solving time," parents get to set the agenda -- first listening to a child's perspective on a problem, then offering their own. And Greenspan is a firm believer in the importance of setting limits, as long as it's done in conjunction with floor time: the more limits, the more floor time. Otherwise, he says, life degenerates into a power struggle. But pervading all your interactions with your child should be the spirit of empathy that is at the core of floor time. Floor time, says Greenspan, is not just "a specific half-hour . . . it's a philosophy, in terms of the way you relate to the child all the time."

Some parents who have tried Greenspan's approach find his floor-time philosophy alienating. "I felt like someone was trying to enforce togetherness with my child, when I had togetherness with him already," says one mother of her experience with Greenspan, whom she and her husband had consulted about their 2-year-old's biting problem. (As with all the Greenspan patients interviewed for this article, I was not referred to this woman by Greenspan himself.) Maybe floor time makes sense in theory, she says, "but it also made me feel totally inadequate."

Others have an attitude toward Greenspan that might be characterized as reverential.

"I feel like I need a dose of Greenspan every six months," says Mary Carpenter of Northwest Washington, a regular Greenspan reader who has boys ages 4 and 7.

First Feelings, says Colette Silver of Chevy Chase, whose three children range in age from 4 to 8, is "one of those books you keep in the bathroom, and you go in there and you read it, and you come out feeling inspired." She and her husband, Michael -- a psychiatrist himself -- have found floor time to be a "miracle cure" for problems like sibling rivalry and difficulty adjusting to school.

As for me, I'm thinking: What parent wouldn't be willing to spend half an hour a day on a miracle cure? IT'S 20 MINUTES TO 5 when I rush in the front door, greet my kids and the babysitter, hurriedly put away a few groceries, start the rice for dinner, and answer the phone. I decide to leave the mail unopened and the messages on the answering machine unheard. I've scheduled half an hour of floor time with my son, and I'm running late.

At 5 I whisk Sam upstairs to his room, away from the phone and the TV, and shut the door. In the sudden quiet, we sit somewhat awkwardly side by side on the edge of his bed, trying to figure out what to do. After a few minutes of slightly stiff conversation, there's a tentative knock at the door. It's the babysitter.

She says she's sorry to disturb us, but our next-door neighbor has just come by to invite my kids over to put up Halloween decorations.

Sam looks at me imploringly. I should have known better than to try to do this on the afternoon of Halloween.

"It's okay," I tell him, feeling deflated.

He bolts.

Not all of my early attempts at scheduled floor time are as abortive as this, but the general rule is that nothing turns out as planned. The first problem is what to do with one child while I am doing floor time with the other. Greenspan insists that it's possible for an adult who's alone with more than one child to do group floor time: Each child gets to be the leader for 20 minutes. Parents who have tried this say it's difficult at best, and my own initial attempt confirms their view: We never get past the bickering over who's going to be leader first. Besides, I sense that one of the main attractions of floor time for my kids is not having to share me with anyone, especially not a sibling.

So by now I have arranged for a babysitter or a grandmother to be around several afternoons a week. That solves the problem of what to do with the other child, but other obstacles to floor time present themselves: Sometimes the kids are tired when they get home from school, sometimes they just aren't in the mood, and sometimes -- as on Halloween -- unexpected distractions pop up.

But I notice that, while floor time isn't always happening when I've planned it, it sometimes happens when I haven't. Often this occurs in the evenings, when life is generally more relaxed. On Halloween night, for example, while my son lay in bed pleasantly exhausted from a round of trick-or-treating, we had a lovely, warm, giggly 15-minute conversation -- a conversation that felt far more natural than the scheduled floor time that afternoon.

It begins to dawn on me that the period between dinner and bedtime -- when my husband and I have always divided up the kids and spent time with them one-on-one -- is the obvious place for floor time in our schedule. Even with two parents who are home for dinner almost every night, I soon realize that it is virtually impossible for us to make time for each child, every night. But when we can, my husband and I will approach that after-dinner time with a slightly different mind-set, following our kids' leads and tuning in to their feelings. WITH HIS BALDING HEAD, tweed jacket, baggy chinos and a pair of shoes that look like a cross between bedroom slippers and Birkenstocks, Greenspan, 54, appears slightly eccentric but friendly and approachable. Which in fact he is.

"He looks like everybody's favorite pediatrician," says Marianne Roche, a mental retardation services administrator for Montgomery County, Pa., who heard Greenspan speak in Allentown last year and was so impressed that she invited him up to give a daylong workshop. He's a skillful speaker, animated and funny, with a knack for the catchy phrase. He talks rapidly and without notes, in a voice tinged by his New York origins, and -- in keeping with his emphasis on interaction -- he welcomes interruptions from the audience. While I found him much the same offstage as on, some parents who have consulted him have called him aloof or abrupt. Says one mother: "He's more engaging with an audience of 600 than he is one-on-one."

Greenspan's own childhood was a fairly typical one for the '40s and '50s. His parents were upwardly mobile first-generation Eastern European Jews who started out raising their two boys in a modest Brooklyn neighborhood, and then, when Greenspan was 10, joined the trek to the newly burgeoning suburbs of Long Island. His father, who eventually owned his own metal-finishing business, worked six days a week. His mother stayed home with the kids.

And, although it was a warm, emotional family -- "Everybody was in each other's business," Greenspan recalls -- floor time was definitely not part of the routine. In fact, Greenspan's mother used to tell him that he was such an easy, independent baby that she would leave him outside the house in a crib while she was inside doing chores. In retrospect -- knowing, as he does now, that his essential nature is gregarious -- Greenspan suspects that he actually "wasn't so tickled at being left alone."

In school, Greenspan encountered another problem that helped shape his professional outlook: Although he was good at math and science, reading and writing didn't come easily. To this day, he finds it arduous to read a book, and he never does it for pleasure. And, despite the string of books he's authored, he never writes for the popular market without a collaborator to polish his prose -- his wife, Nancy, for the first two books, Washington Post staff writer Jacqueline Salmon for the last two.

But starting in seventh or eighth grade, Greenspan began to figure out ways to compensate for what today would almost certainly be considered a learning disability. Instead of struggling to read a whole book, he learned to look for the key concepts and focus on those. Instead of laboring to turn out a well-crafted, perfectly spelled essay -- something he knew he could never do -- he would come up with a new twist or a fresh insight.

By the time he was a senior at Harvard -- to which he gained admission, he says, partly on the basis of his talent for playing football -- he had honed his approach to a science. That summer, he distributed notices to graduating high school students announcing that he would be teaching a college preparatory course based on the principles he had developed.

This anecdote displays in microcosm the pattern of Greenspan's career: identifying a "challenge" (one of his favorite words -- it appears in the title or subtitle of at least three of his books), coming up with an innovative solution, and bringing it -- with perhaps a touch of arrogance -- to the masses. But the experience of learning to overcome his problems with reading and writing also helped Greenspan to arrive at two insights that permeate his work.

"One," he says, "that kids have different learning styles that are real and need to be paid attention to. And two, that people have an enormous capacity to use their strengths to compensate for any areas of vulnerability."

In writing about the school-age child, Greenspan has often focused on the way a child's individual strengths and weaknesses can interfere with learning -- and he is deeply suspicious of labels, like "attention deficit disorder," that lump groups of children together. Perhaps because of his own background, Greenspan is adept at coming up with analogies to illustrate what it feels like to be a kid whose sensory profile makes learning difficult: Imagine throwing a curve ball with your left hand, he says, or winding your pencil through a maze that's reflected in a mirror. You can do it; it's just tougher.

And his books brim with suggestions for helping kids compensate for their areas of weakness. If a child is having a hard time expressing himself through writing, he suggests, try giving him a tape recorder to talk into -- and don't be surprised if you get an outpouring of creativity. Perhaps not coincidentally, that's the writing method Greenspan uses himself.

Greenspan envisions an educational system that incorporates, as much as possible, the key elements of floor time. Before children can learn to read and write, he says, they must first master the emotional skills of engaging, interacting and communicating -- and schools need to take into account the fact that children master these skills at different ages. Teachers must know each student well enough to be able to assess his or her readiness for the next stage of learning. Instead of large classes doing work sheets geared toward standardized tests, Greenspan favors small interactive groups of children of mixed abilities exploring open-ended questions.

"The only children large-group teaching works with," he says, "are children who could teach themselves -- children who don't need to go to school." Most learning, Greenspan says, does not occur when children are poring over a workbook or puzzling out a math problem, but rather in the "split-second initiatives" that occur when they interact with teachers, fellow students -- or, of course, parents. "LADIES AND GENTLEMEN," I am saying to my empty family room, in a reasonable facsimile of a circus ringmaster's booming voice, "introducing Alisa the Amazing Baby Elephant!"

Sophie lumbers on all fours to center stage -- the family room rug -- where I put her through her paces. She rolls over, shakes hands, stands on her hind legs, all to the accompaniment of my enthusiastic cheering and clapping.

"Isn't she amazing, folks?" I say, as Sophie takes a deep elephant bow.

After several weeks of more or less systematic floor time, Sophie has invented this game -- which we will continue to play, with minor variations, for weeks to come. I have no trouble locating Sophie on Greenspan's developmental road map: The world is definitely her oyster.

At first, our playing together had a wooden quality. I knew Sophie was capable of spinning out complicated fantasy plots when she was playing by herself or with her friends, but when playing with me -- perhaps because she felt self-conscious -- she seemed to expect me to take the lead. I was reluctant to do so; the whole idea of floor time was to let her take the lead. And I felt a little silly and self-conscious myself.

Over time, though, we both grew more relaxed. Soon we had our downstairs toys (the dollhouse and a toy playground) and our upstairs toys (tigers, zebras, ducks and a few dinosaurs). Each set of toys had its own continuing plot, like a TV mini-series -- we could call it "Upstairs, Downstairs," I thought. We didn't have to bother with the preliminaries of coming up with a scenario and assigning roles each time we played; we could just plunge right in where we left off.

Now, with Alisa the Amazing Baby Elephant, we've transcended toys. It's just me and Sophie and our imaginations.

Are we having fun yet? Well, yes and no. Sophie clearly is. In fact, my biggest problem is extricating myself when our half-hour is over -- sometimes our floor time stretches to an hour or more, and even then Sophie has a hard time calling it quits. And she's gone from being a child who could entertain herself for hours to one who begs me to play with her several times a day.

It's gratifying to see her respond so enthusiastically, and I do sense that floor time is filling an important need. While Greenspan cautions parents not to play shrink, he also predicts that themes will emerge in a child's pretend play that have a strong relationship to real-life emotional experiences. And I can see this clearly in my floor time with Sophie. In games like Alisa the Amazing Baby Elephant, she's getting a chance to be the star of the show -- something that a younger sibling often finds all too difficult in the family drama.

Other plots have carried similar echoes of her daily life: The black-haired kids from the toy playground decide to exclude the blond-haired kids, or the girls refuse to play with the boys. After Sophie suffered a series of ear and strep infections, the dollhouse brother fell ill and the doctor began to visit the dollhouse and prescribe medicine -- and baths, with hair-washing -- three times a day. Eventually, this led to a plot development that became one of Sophie's favorites: The doctor was savagely attacked by the toy shower.

But, while I believe in the value of what we're doing, I find that engaging in the same fantasy game over and over can be excruciatingly boring. My mind starts to wander; my eyes start to close. I think back to Greenspan's belief that when a parent gets bored, it's often a sign of discomfort with the theme that the child has introduced. Parents, he says, need to be aware of whatever baggage they bring to the interaction, and not change the subject if the child hits a raw nerve.

Am I just bored, I ask myself, or do I have some deep-seated aversion to the scene we're playing out? The only theme I can think of that might make me uncomfortable is that of aggression -- and in our early floor-time sessions, I noticed that this was one theme Sophie never introduced.

When she finally did, I was thrilled. But, I sometimes wonder, do I really have enough self-awareness to figure out my own psychological makeup, and how it might be affecting floor time? Am I being too controlling? Too passive? How do I know if I'm doing this right?

There's a downside to parenting experts, even the best ones: They tend to ratchet up self-doubt. "NO, NO, NO, NO!" Greenspan's voice is booming. "Absolutely not!"

Greenspan is talking not to me, but -- on videotape -- to the father of a 14-month-old; the parents have consulted him because their baby is not engaging with them well. As he often does in his clinical practice, he has taped the parents playing with their child. Greenspan generally sees patients only once every month or two; during those sessions, he tries to provide parents with the guidance they need to do the day-to-day therapy themselves.

On the videotapes Greenspan's disembodied voice coaches the parents along, sometimes dispensing praise, sometimes offering suggestions, and sometimes -- as just now -- telling them in no uncertain terms that they're doing something wrong.

What the father has done is something that most parents, especially fathers, are wont to do when racking their brains for a way to amuse a baby: He has picked up his son and twirled him upside down. While this gambit is sometimes a fine way to interact, Greenspan says, here the child was just beginning to take some initiative in playing, and the father "took over" his body. Beyond that, Greenspan has told both parents that they're too passive. (To me, they look pretty ordinary.)

"When you play with him," he tells the mother after she's been playing a game of go-find-the-ball with the baby for several minutes, "I want you to be a little more joyful, a little less tense. Challenge him, inspire him to be a little more interactive."

Watching Greenspan's videotapes -- which he uses as teaching and lecturing aids -- you begin to see just how complex a balancing act floor time can be, and how some parents have an easier time with it than others.

"This is tough," one mother says in exasperation after trying and failing to interest her 1-year-old daughter in a succession of toys. The baby is in Greenspan's office because she wakes up at night and wants to be entertained. Greenspan's prescription is to get her to take more initiative during the day; eventually, he predicts, she'll be more self-sufficient at night.

Seeing that the girl has put a plastic tiger in her mouth, Greenspan suggests that the mother try putting it in her own mouth. Greenspan himself has no self-consciousness about this sort of thing -- Newsweek once ran a photo of him confronting a baby with a toy banana in his mouth -- but the mother looks dubious.

Greenspan demonstrates what he wants the mother to say. "Oh," he wheedles in a high-pitched voice, "can I taste that tiger, too? Oh, please? I'm going to take it!" Then his voice switches back to its normal register. "Go ahead, Mommy -- take the leg with your mouth."

The mother clamps her teeth around one of the tiger's hind legs and gently pulls it out of the baby's mouth. The girl gives her a look of surprise and delight.

"There," says Greenspan. "That's the first big smile we've gotten. Do it again."

But with another child, Greenspan sees a parent's interest in playfully taking away a toy as being overly controlling. A father is trying to join his 3-year-old son, who has been diagnosed with a low-level form of autism, in a good guy/bad guy scenario.

"I've got two guns," the boy says.

"Who are you going to shoot?" the father asks.

"Here's a good opportunity to go with the flow," Greenspan interrupts. "He says, I've got two guns.' You say, Boy, you've got a lot of guns!' "

"Can I say, Can I have one?' " the father asks.

"That's your agenda," Greenspan tells him. "Empathize with him." Greenspan is thinking that the father's question reflects a desire to take away, symbolically, the boy's power. He also wants the father to stop asking so many questions -- his natural style, Greenspan sees, is to keep the vocal interaction going -- and to focus more on what excites or interests his son.

Clearly, some of this is far from intuitive. But Greenspan is convinced that the vast majority of parents can manage to do it successfully.

"You have parents who do this easily," he says, "and you have parents who do it, but with a lot of introspection and discussion . . . But in all cases, setting out on this journey is very useful. And in fact, the more trouble you're going to have with it, the more valuable it's going be to you in a personal sense, not just for your children."

The whole idea of floor time grew out of Greenspan's work with a group of parents who would be likely to have trouble with it. In the late '70s and early '80s, he headed a National Institute of Mental Health study of multi-risk families -- families plagued by mental illness, substance abuse, domestic violence, families that the mental health community had concluded were basically beyond hope. The idea was to identify families where an older child was already in trouble and the mother was pregnant, and to work with the mother to prevent problems from occurring with the child who was on the way.

From observing the interaction between these mothers and their children -- as well as a control group drawn from normal families -- Greenspan and the clinical director of the study, psychologist Serena Wieder, drew a number of conclusions. They saw that infants and young children progress through a series of emotional stages, and that babies respond differently to external stimuli. These were concepts, Wieder says, that had been around in an abstract way, "but through the study we learned how those differences affect parent-child relationships."

Some parent-child combinations clearly held the seeds of disaster: an underreactive child and a depressed mother, or a mother so sensitive to rejection that when her child introduced that theme in pretend play she would take him literally and stop playing. In those cases the children were not progressing as they should have through the developmental stages. But Greenspan and Wieder saw that many of the mothers -- despite their overwhelming problems -- could be helped to play with their children in a different way and get them back on track.

Greenspan also has videotapes from that study, and watching them is both sobering and reassuring. When you see a depressed mother staring blankly into space, holding her nursing infant as though the baby were a log, or later, bouncing her baby vigorously despite the child's intensifying protests, you think, that kid's in trouble, but you also think, I would never do that. And when that same mother, after two years in the study, is able to engage in what looks like floor time -- giggling with her toddler while playing with a toy phone -- you think, well, great, but that's just what I would do.

It's when the idea of floor time is applied to more subtle problems that things get trickier. A parent's style of interaction might not be objectively wrong -- it might be fine for some kids -- but, in Greenspan's view, it might be wrong for the particular child that parent happens to have.

The father who wanted to ask his son for a toy gun recalls that, at the end of their first session, Greenspan said, "Okay, I'm going to teach you how to play with your child. Come back next week." The father recalls those words as a beacon of hope. "I was losing my son," he says, "and I needed to get him back."

But some parents who have consulted Greenspan about less severe problems (he sees a wide range of cases, from kids who are just afraid of the dark to kids who have been diagnosed as autistic -- see accompanying story, Page 31) have bristled at his critiques.

Greenspan stresses the importance of affect. He cautions parents against pretending, for example, that they're not angry or upset when they really are. "A child responds more to your affect and emotional tone than to your words," he says. "Parents shouldn't try to be great actors." Yet some of his advice to parents is directed at getting them to change their affect. Rev it up for an underreactive child, he'll say, or slow it down for one who's hypersensitive. When you're setting limits, be Smokey Bear -- gentle but firm.

One mother recalls that when she brought her 2-year-old to Greenspan because he was having trouble adjusting to preschool, Greenspan told her she was talking too fast. To encourage her son to be more assertive, she should slow down and play dumb, along the lines of the TV detective Columbo.

"I am who I am," this mother says. "I felt like he was saying I was not acceptable for this kid." IT'S FRIDAY LUNCHTIME, and the Mazza Gallerie McDonald's is in its usual state of chaos. Kids are everywhere, tossing food, standing on chairs, laughing, yelling. But I am focused on only one child: my son. I am trying to draw him into a conversation.

Although Sam has occasionally allowed me to join him in pretend play, or at least to hover around the edges, it's clear that he would prefer to just play by himself. Unlike Sophie, he's old enough to feel self-conscious about the products of his own imagination. Floor time for us has been a mixed bag. Sometimes we build with Legos, sometimes we play a board game, sometimes we sort his baseball cards. Any of these activities can count as floor time, Greenspan says, as long as your child is in charge. If he wants to play a board game by his own rules, that's fine -- as long as it's floor time. But often, Sam and I find ourselves stuck at the stage of settling on an activity.

What I'm hoping today is that we can engage in chitchat -- also a floor-time activity -- and maybe I can even gain some insight into the opaque world of second grade. As with many kids his age, Sam's routine answer to the question, how was school today, is: fine. Period. Any further inquiries and he's liable to say something like, "What is this, a pop quiz?"

To my delight and surprise, Sam pauses in the consumption of his Happy Meal and spontaneously brings up a subject related to school. He complains about a teacher who he feels treated him unfairly. His description is vague, and my impulse is to start asking questions: What happened? What did she say? What did you say?

But I suppress the urge. What Greenspan recommends in a circumstance like this is empathy. Instead of passing judgment, you show your child you understand how he feels without necessarily agreeing with his analysis of the situation. Try bringing up some analogous experience from your own childhood, he suggests.

So I delve into my memory and start talking about how, when I was 8, my math teacher put my name up on the board after I'd flunked tests in multiplication and long division -- subjects that had been taught the previous year in third grade, which I had skipped.

"It was so unfair," I say. "And it was -- I don't know -- embarrassing."

Sam looks at me for a second with a mixture of surprise and appreciation, as if to say, "So maybe she does understand, after all."

And then, lo and behold, he keeps talking -- not about the specifics of the incident, which I never do learn, but about something much more important: his feelings. If I had tried to pry concrete information out of him, he almost certainly would have clammed up. Hey, I think, this Greenspan stuff really works. But another day, when I bring up what I think is an empathetic analogue from my own childhood, Sam doesn't rise to the bait. "I don't need to hear your life story," he mutters. EVERY SPRING, Greenspan runs a three-day session in Bethesda designed to give others in the field of child development a crash course in his methodology. Last year, he says, it drew almost 600 people from around the country. Ultimately he hopes to have a nationwide network of therapists who use his approach, so that when parents come in from out of town to consult him -- which about half of his patients do -- he'll have someone back home to refer them to.

Yet there is a paradoxical aspect to Greenspan's apparent popularity within his profession: Most of those who have embraced Greenspan's ideas are speech pathologists, occupational therapists, teachers, social workers and psychologists. While his fellow psychiatrists and psychoanalysts know and respect him for his early work on infants' emotional development -- for which he won two of psychiatry's most prestigious awards -- they tend to be less familiar with his more recent writing.

"Part of me hates to say this," says Paul Prunier, a local psychiatrist who has himself found Greenspan's approach useful, "but even in the analytic community Stan is seen as being sort of on the fringe."

To some extent, the more visible Greenspan has become to the non-psychiatric community, including parents, the less visible he's become to his professional peers. T. Berry Brazelton, a professor of pediatrics at Harvard Medical School who has become a household name through his own mass market books, applauds Greenspan for taking his message directly to parents. But Brazelton -- who serves with Greenspan on the board of the Zero to Three National Center for Clinical Infant Programs, a foundation Greenspan started -- says popularization "takes a lot of courage, because you certainly don't get any credit from your profession for doing it."

Eleven years ago, when First Feelings was published, Greenspan was at a professional crossroads: He'd been with NIMH for 19 years, had a string of scholarly publications and was a big name in his field at a relatively young age. He had his pick of academic job offers. But he chose to forge his own path, a path that has led him to straddle two worlds. Now he's both a parenting guru and someone who wants to be taken seriously as a scholar.

Taking the initial plunge into the popular market was not easy for Greenspan. His wife, Nancy (his collaborator on First Feelings), worked hard to persuade him to use the pronoun "you" instead of "one." And he chose Viking Penguin over another publisher that offered more money but demanded, Greenspan says, "a rewrite that would make it more user-friendly and, I sensed, jazz it up more.

"At the time, I think I was very self-conscious about keeping the book very honest, very scientific, very straightforward," he says. "I wanted it to be something professionals would respect instead of just a parenting book."

And, he says, he succeeded. Many professionals, including psychiatrists, first became acquainted with his theory of emotional development through First Feelings -- a book that is readable but dense. But Greenspan's more recent popular books are, well, jazzier. The prose is punchier, and problems are illustrated by lengthy case studies of pseudonymous families that read almost like short stories.

"I got braver," Greenspan says.

While psychiatrists aren't likely to have read Playground Politics, Greenspan points out that he has continued to publish in peer-reviewed journals and to write scholarly books. Some psychiatrists may perceive him as a popularizer and therefore overlook his more technical writings, he says. Another reason he may be overlooked, he says, is that the recent trend in psychiatry is away from therapeutic approaches like those he offers and toward more biological, drug-based methods.

When a new drug hits the market, he says, psychiatrists are quick to start using it. But where a new therapeutic approach is concerned, "medicine and science are very slow moving. For a concept like floor time to become an attractive concept that all psychiatrists would want to use, it could take 20 years."

In the meantime, popularization proceeds: Greenspan is spreading the word to anyone who cares to listen. SEVERAL MONTHS into a more or less regular program of floor time -- plus a few stabs at problem-solving time and limit-setting -- I ask myself: What have I got?

Not a miracle cure, certainly. But I do have something: We still have our share of squabbles and worse, but -- some of the time, at least -- my kids and I are more apt to engage in dialogues about our emotions instead of just experiencing them. Sam has begun to allow me into the world of his imagination, just a bit. Sophie, who has come to accept the fact that I can't always play with her, often displays a newfound ability to put her feelings into words. Floor time has become less a sacred-but-artificial half-hour, and more a way of life. And I don't spend as much time as I used to wondering whether what we're doing actually counts as floor time. Anything can be floor time, as long as you're interacting; it's your attitude that counts.

We have our bad days, when floor time seems sluggish and unfocused and I check my watch repeatedly. But we also have our good days, when my kids and I are in synch and we laugh spontaneously and I feel like I'm connecting not only with my children but also with the playfulness and uninhibited powers of imagination I thought I had lost along with my own childhood. A couple of times we've even managed group floor time. One evening Sam organized a kind of baseball game in our family room, after which the three of us played with Sophie's dollhouse. Granted, the plot twists reflected Sam's influence -- the little brother caught rabies, and the cat burned her tail in the fire -- but it was a start.

"Don't try to formula-ize parenting," Greenspan told me as I was reporting this article. At the time, I wondered if that statement undercut his own work. Wasn't he offering a formula himself? Like other parents I've talked to, I've felt at times that I had an imaginary Dr. Greenspan perched on my shoulder, observing all of my interactions with my kids. In a difficult situation, I often felt tentative and confused, not knowing what he would advise -- and I was frustrated that I wasn't able to react spontaneously. But I've come to realize that what Greenspan is really offering are general principles -- listen, empathize, interact -- that work best if you can internalize them so that they become a part of your parental instincts.

To the extent that I've been able to do that, my dealings with my children have improved in subtle, but important ways. I've found that now, for example, when my kids bring up something that's on their mind -- which they've been more apt to do since we instituted floor time -- I automatically slow down and try to see things from their perspective. And because a greater percentage of our time together is spent doing things that are far more pleasant than engaging in power struggles, our relationship is -- overall -- warmer and closer than it was six months ago.

There are moments, however, when it all flies out the window. Reading The Challenging Child, I was heartened to learn that about once a week Greenspan loses it and yells at his kids in what they refer to as his "killer voice" -- it's made me feel less like a failure when my own voice has taken on a murderous cast, as all parents' voices inevitably do at times. It is humanly impossible to remain constantly tuned in, no matter what provocation a child throws in your way. But, as Greenspan would say, it's a goal. And even if you never make it all the way there, you may yet produce children who grow up to be warm, empathetic, self-confident and creative.

I'll let you know in 20 years. Natalie Wexler, a Washington writer, is a frequent contributor to the Magazine. CAPTION:Two-Career Time Crunch Can workaholic parents really have it all?

In many affluent Washington families, one parent -- usually the father -- routinely works past dinnertime, or even past the kids' bedtime. In some cases both parents adhere to that kind of schedule. Those families, Stanley Greenspan feels, need to rethink their priorities.

"It's very hard if both parents are lawyers and working till 8 o'clock," he says. "There's just not enough time, there's not enough chicken soup for everyone."

Often, Greenspan says, people don't anticipate the demands that parenthood will place on them. When you're young and childless, he says, it's easy to satisfy the work ethic: You stay up late, you work hard, and you get the psychological equivalent of an A+. Then along come kids, and if you continue to try to get the A+ at work, you find that you're getting a C+ at home. "And as you look at it realistically, you say, okay, the best I can do are B+'s with everyone," Greenspan says. "Because if I give my kids what I think they need ideally, this marketing report or whatever is only going to be a B+ report."

Some people who've been striving for A+'s all their lives find it hard to imagine deliberately planning to achieve anything less. Those parents, Greenspan writes in Playground Politics, should make it a rule to be home from 6 to 8:30 for family time: "After that, you can work at home or go back to the office -- until 3 a.m. if you need to."

When parents consult Greenspan in his clinical practice, he'll sometimes draw an analogy to a medical emergency. Speaking at a conference on autistic children in suburban Philadelphia, Greenspan described a speech he gives to workaholic fathers: "What if your child needed kidney dialysis every night and you were the only one who could put him on the machine? Would you come home? Would you lose your job if you did?"

While the high drama of this approach might carry some weight with parents of children with serious problems, parents with more run-of-the-mill issues can find it laughable. One father with a fussy infant recalls that Greenspan advised him to treat the problem "like it was cancer."

Another real-world fact intrudes on Greenspan's ideal parenting prescription: In most two-career families, when one career has to give, it ends up being the mother's. His own family is no exception.

When his three children -- now 13, 16 and 18 -- were young, he worked long hours, heading a major research project at the National Institute of Mental Health and seeing private patients as well. Greenspan's wife, Nancy, had had a promising career of her own as a health economist -- a career that she assumed would continue uninterrupted after they started a family. "But Stanley and I sat down before the baby was born," she says, "and it was clear he had a completely different picture."

Nancy scaled back to part-time work after their first child was born. Eventually, with the birth of their third child, she decided to stay home full time -- a choice that she says was difficult, "but clearly the right thing to do."

Stanley Greenspan always spent time with his kids -- he rocked his oldest daughter, Elizabeth, to sleep just about every night when she was an infant. But inevitably, it was Nancy who did the lion's share of the child-rearing -- including, under her husband's direction, floor time.

"He hadn't coined the phrase yet," says Nancy. "But Stanley clearly had that concept from day one with our first child. He would say to me: Make sure when you get home from work that you play with her! And he was giving me all the steps of effective floor time."

About 10 years ago, Greenspan left NIMH and reorganized his schedule so that he spent much more time at home. Monday, Tuesday and two-thirds of Wednesday he sees patients in his home office. The rest of the week he reserves for research and writing. Clearly, there were important factors in his decision other than a desire to spend more time with his kids: an aversion to bureaucracy and endless meetings, a desire to have a more hands-on career than he would have had if he'd joined a medical school faculty. But also, he says, "I didn't realize how much I was missing." Being home every night for the spontaneous family interaction that occurred around dinnertime helped him feel much more involved in the details of his children's lives.

At around the same time, Nancy was getting increasingly involved in volunteer work on environmental issues in Montgomery County. She points to her own experience to illustrate that you don't necessarily need a job to get pulled away from your responsibilities on the home front. A few years ago she realized that she was attending meetings several nights a week, and decided she needed to rein in her activism to spend more time with her rapidly aging kids. "If I don't see 'em now," she thought, "I don't see 'em."

Recently Nancy took a part-time job as a consultant to Pepco on energy conservation, and Stanley maintains a workload that sounds staggering: five books in various stages of development, speaking engagements as often as once a week, and so many would-be patients that there's a three- to four-month wait for an appointment. But on a Thursday or Friday afternoon both Greenspans might well be at home -- a comfortably crumbling 90-year-old farmhouse in the wealthy Edgemoor section of Bethesda -- to greet 13-year-old Sarah when she ambles in from school, or to run out to cheer at 16-year-old Jake's basketball game.

One thing he's found from his own experience, Greenspan says, is that floor time gets harder as kids get older. "They're all so busy, they much prefer being with their friends. When they're younger, you can pick your spot. Now, as they get to be teenagers, you kind of look for the opening. When they're getting ready for bed, you kind of mosey up, or you try to extend dinner a little longer." Or you try to get a conversation going in the car.

"In retrospect," he says, "I wish I had lightened my load a little earlier." - N.W. CAPTION:Floor Time and Autism

Perhaps the most dramatic -- and controversial -- application of Stanley Greenspan's floor-time philosophy has been in his work with children who have been diagnosed with pervasive developmental disorder (PDD), a mild form of autism. He has challenged the received wisdom that autistic children are born without the capacity to interact with others. The real problem, he says, is that these children are either underreactive or overreactive to noise, light or touch. At age 1 or 2, they become overwhelmed: They want to interact, but it's just too hard.

To unlock these children from their increasing self-absorption, Greenspan recommends what he does for all children: Meet them at their developmental level and interact. With an autistic child, that might mean engaging in what Greenspan calls playful obstruction. If a child is obsessively rubbing a spot on the floor, the parent might cover the favored spot with his hand. The child may become frustrated, but he's begun to interact. With a great deal of time, energy and patience, Greenspan says, the child will discover the pleasures of human interaction.

Some parents who have brought children to Greenspan after a diagnosis of PDD credit Greenspan with saving their kids from a lifetime of emotional isolation. One father named David recalls that at age 2 his son Jake exhibited all sorts of worrisome behaviors: He would obsessively run in circles or shake his head, he had no idea what to do with a toy, and he didn't speak or even communicate nonverbally.

"He couldn't organize himself to point his finger or wave," David says. "He was communicating at the level of a 5- or 6-month-old." Now, after two years of therapy under Greenspan's supervision, "if you saw him in a room with five or 10 other kids, you wouldn't know the difference. He wakes up and starts talking and he doesn't stop till he goes to bed."

One mother in Northern Virginia was shocked when a Fairfax County agency that tests preschoolers told her that her 3-year-old son had PDD and recommended special ed classes. At home, she says, her son was "an extremely bright, very verbal, perky, sweet little boy." But his preschool teacher had noticed troubling signs: He echoed phrases and didn't engage in symbolic play. And during the testing, the boy refused to answer even simple questions. Like David, this mother refused to accept the diagnosis. She found Greenspan two years ago, and today, she says, her son is "a different kid." She expects him to be enrolled in a regular kindergarten class this fall.

Greenspan prescribes a lot more than just half an hour a day of floor time for these kids. Parents are told to do floor time six to eight times a day and engage in a time-consuming and budget-draining round of private therapies: speech therapy twice a week, occupational therapy twice a week, individual play therapy once a week and group therapy once a week. Every few months the parents check in with Greenspan, who also supervises the various therapists through regular team meetings.

Obviously, this approach requires major parental sacrifices. "It's definitely a therapy for the haves and not for the have-nots," says Josh Fader, a local psychiatrist who treats children with severe developmental disorders and endorses Greenspan's approach. And while Greenspan has had some undeniable successes, there are those who feel, as Fader puts it, that he's "selling way too much hope to families."

"I think people are waiting to see hard research from him," Fader says. "But I think we're going to see the world of autism turned upside down." - N.W.