In a Word, It’s Tough : Books: Writing for kids isn’t as easy as it may look, especially since young readers always can spot a phony.

So, you want to write a children’s book?

You’re thinking it would be a cinch. Certainly easier than writing for adults. Action, small words, a little mystery, some cute animals.

How hard can it be, after all, to engage the mind of a 6- or 9- or 12-year-old?

Harder than most imagine say those who have done it. Barbara Bottner, a Los Angeles writer and illustrator of 20 children’s books, meets people with publishing presumptions all the time--at parties, around the neighborhood, even among her students at the Otis Parsons Art Institute, where she teaches a course on writing children’s books.

“Most people think: ‘I’ve been a kid. I have a kid. My kid likes my bedtime stories. I can write children’s books,’ ” said Bottner.

“(To write children’s books) you have to understand voice, humor, pacing, dramatic tension, emotional accessibility. . . . You really have to know how to write, and that takes a lot of work and practice,” said Bottner, who has been working at it for 18 years.

Her message is echoed by those who publish and review children’s books. The world of children’s literature, they warn, is not a boot camp for those hoping to write the Great American Novel.

“The notion that you can write children’s books easier than other kinds of books because you can slip something by a young reader is simply wrong,” said Kathleen Tucker, editor-in-chief of Albert Whitman & Co. Of the nearly 3,000 manuscripts the company receives, it publishes only about 25 children’s books a year.

But even if your book gets published, it still needs to engage young readers. And they may be the hardest ones of all to impress.

“Sometimes children are more perceptive and won’t make allowances the way adults do,” said Barbara Ellemen, children’s book editor for the publishing industry’s journal, “Booklist.”

“Children won’t sit through a long, leisurely beginning. They want the story to start, the action to start. They want a believable ending,” Ellemen said.

But even though getting your children’s book on somebody’s bookshelf is never easy, now may be one of the best times to try.

Not only are children’s books replacing the traditional reading primers in schools, there are also more children today to read your book.

“The number of kids under the age of 5 climbed 11.8% in the 1980s, and that trend is supposed to continue until 1996,” said Diane Roback, children’s book editor of Publishers Weekly. “You also have the best-educated generation of parents yet. They know the value of books.”

The last decade also has seen a boom in bookstores devoted to children’s books, from about 50 to more than 300 today, according to Caron Chapman, executive director of the Assn. of Booksellers for Children.

Children’s books have enjoyed some big successes in sales, especially paperback series like Ann M. Martin’s popular Babysitter Club books.

Not only have children’s books grabbed almost 50% more of the general book market since 1979, but revenues from these book sales are among the briskest of any in the publishing business.

“The Polar Express,” a Christmas tale written and illustrated by Providence, R.I., artist Chris Van Allsburg, has spent every Christmas season since 1986 on the New York Times Best Seller List. It costs $16.95 and obviously sells phenomenally well.

Houghton Mifflin, Van Allsburg’s publisher, reports that the number of copies sold just cleared the 1-million mark. The standard cut for authors is 5% of sales price, and it is the same for illustrators. So since Van Allsburg is both, he makes at least $1.69 for each book sold.

You do the rest of the math. Then calm down and listen to what Norma Simon, author of more than 40 children’s books over the last 40 years, has to say about the incomes of most children’s authors.

“It has been a very happy career, but not a very lucrative one,” she said recently from her Cape Cod home. “It’s just like show business: you only hear about the stars. I’m considered successful, but I’d be at the poverty level if I had this as my only means of support.”

Simon prefers to talk about the intangible rewards that come from writing something that helps children better understand their world or feel less alone in a bewildering situation--divorce, for instance.

Simon writes “concept” books, which deal with issues in the emotional life of children. Much of her research takes place at nearby Welfleet Elementary School, where Simon teaches creative writing to youngsters from kindergarten to sixth grade in exchange for no-holds barred critiques of her work.

Recently, she read the children a draft of her new book, titled “Nobody’s Perfect, Not Even Your Mother.” She got to a scene in which the mother comes home and reacts--unfavorably--to a mess the family dog made on the living room floor.

“The children stopped me right there. They said ‘Oh no, not the floor. The carpet ! That will really upset her!’ ” Simon recalled.

Barbara Bottner’s method is to dredge up the feelings of her childhood, then work out a theme and narrative that recreates them in the experiences, language and behavior of her characters.

“You are writing from the child in you,” she said. “You are not writing from a distance about what you see children do.”

Bottner has no children, and she did not initially set out to write books for them.

She studied art in college, then worked in the theater, supplementing her earnings from off-Broadway productions with a job teaching arts and crafts at a Brooklyn senior citizens’ center. It was only when a freak accident on the stage laid her up with a broken leg that she hit on the idea of using her drawing skills to illustrate children’s books.

For texts, Bottner turned to successful writers she knew in New York, mainly playwrights she had met through her work in the theater. But publishers repeatedly rejected the manuscripts, saying they were not children’s books. Finally, one editor, who liked Bottner’s art, suggested she try writing the text as well.

The result was, “What Would You Do With a Giant,” published in 1972, a conversation between two small boys, each trying to outdo the other’s suggested use for a giant.

The final page has the boys agreeing that giants don’t really exist while the giant of their imaginations stands tall in the tree above them.

While that may seem like nonsense to an adult, it wouldn’t to a preschooler for whom the imaginary and the real are often intertwined.

This is what Bottner means when she talks about writing “from the child within.” Her best students--and most of the successful children’s authors she knows--have maintained this bridge with childhood. Others have gone through her class, Bottner said, not knowing what she was talking about.

But Bottner doesn’t get upset anymore when people suggest that what she does is easy. She’s accustomed to adults smiling patronizingly at the world of children and at those whose work links them to that world. Bottner now smiles back.

It’s a smile similar to the one Norma Simon employs at the big cocktail parties that dominate the summer social scene on Cape Cod.

“I go to them and get introduced as Norma Simon who writes children’s books,” she said. “And everyone always says, ‘Oh, how nice. I’ve been thinking of writing one myself.’ ”