On her frenzied American tour, British author J.K. Rowling was signing copies of Harry Potter and the Sorcerer's Stone when a small boy eagerly approached her.

His words tumbled out in one breath:

"I know what the title of your next book is. I know what it is. It's Harry Potter and the Quidditch World Cup!"

Rowling, a slight woman with strawberry-blond hair, paused to recall the episode, then spoke again in her crisp British accent.

"Every other time a kid has said this to me, I've said, 'No, that's a rumor; that's not the title.' But he was so pleased with himself that he thought he knew it, and he was only about 5, so I said: 'That's right. You're absolutely right.' And I thought, 'He'll deal with it later.' "

The anecdote demonstrates not only the immense popularity of her Harry Potter fantasy series but also her compassion for young readers.

Joanne Kathleen Rowling (rhymes with bowling) is well aware that such fanatical followers consider Harry, Hermione, Ron and the other members of Hogwarts School of Witchcraft and Wizardry like family.

Her first three Harry Potter books are at Nos. 1, 2 and 3 on most best-seller lists. More than 8.2 million copies of the books, which have been translated into 28 languages, are in print in the United States.

As a single mother who spent a few months on welfare, Rowling wrote part of Harry Potter and the Philosopher's Stone (changed to Sorcerer's Stone in the American version) in a Scottish cafe, nursing a cup of coffee while her young daughter slept.

She was born near Bristol, England, and knew by age 6 that she wanted to become a writer. A bright student, she attended a state-run school (not a boarding school) in Chapstow, then Exeter University. She majored in French, taught high school in Portugal, married, divorced, then returned to England.

There, while riding on a train, the idea for Harry Potter and Hogwarts came to her "very nearly fully blown."

The popularity of her books seems to have sprung up likewise.

Recently, Rowling granted an early-afternoon interview at the Four Seasons hotel. (On the street below, adults and children -- some of them wearing costumes and toting broomsticks -- lined up in front of the Borders bookstore where she would appear that evening.)

Q: How did Harry Potter originate?

A: Harry was always a boy, and he was always Harry, but he wasn't always Potter; he had two other surnames. I won't tell you what they were, partly because I'm about to use one of them for another character in book four.

I've thought about why I didn't choose a heroine, but I didn't want to change him. He was too real to me, and it would have felt very contrived to feminize him. . . . There are plenty of strong females in the books. Hermione is a caricature of me when I was younger. Of Harry, Ron and Hermione, she's definitely the brainpower.

Q: Will Harry find romance in book four?

A: He tries, but he doesn't get very far.

They're all kind of after the wrong people, as in life. Hermione gets the first date, and it's quite a cool one because I thought I owed her a bit of fun.

Q: Harry excels at Quidditch, a team sport played on broomstick -- and similar to soccer?

A: No, it's more like hockey, but they score through hoops like basketball.

Basketball is my favorite sport to watch. It's not that popular in Britain. I was in Portugal when I started following the Chicago Bulls. When I got back to Britain, I had to wait until 3 a.m. to watch basketball on television.

Q: A group in South Carolina contends that your books contain violence and promote witchcraft. One woman wants them kept out of certain classrooms. How do you respond?

A: Of course, people have a right to decide what their children read, but I don't think they have the right to decide what other people's children read.

No children's book is going to make everyone happy, nor should it. Children's literature, like any literature, is there to stimulate people. If they think I'm out to promote witchcraft, they're very much mistaken.

Children are very smart. This is a fantasy world in which they totally immerse themselves and enjoy. Then they put the book down and go back to real life.

Q: Children know that a death or two will occur in the next books, and they're worried about some characters -- particularly Ron and Hagrid the groundskeeper. Do you pay attention to such concerns?

A: For five years, this was my internal world. It's still the most amazing thing to meet one person, let alone hordes of people, who knows these characters.

It's heartwarming that people care enough about them to want them not to get hurt, but at the same time I have the absolute right to do what I like to my story and characters. I'm not going to write to order. I've planned the whole story, and I've always known who was going to die and who was going to come through unscathed, and I'm not going to deviate from that.

Q: Have you read Harry Potter to your 6-year-old daughter?

A: I didn't think she was ready for the books, but she begged and begged, so I'm currently reading them to her. We finished the first, and we're halfway through Harry Potter and the Chamber of Secrets. I was very nervous; it's really the most important reading of my life, isn't it? She cries at the end of each chapter and says: "I want more. I want more."

Q: The book jackets for the American and British versions differ. Do you have a favorite?

A: I love the American edition of the books. They look like my fantasy of the books before they were published.

I've now seen 26 different versions, and the American is my favorite. . . . The Italians took off Harry's glasses. . . . I guess they couldn't have a hero in glasses. I didn't like that very much.

The Germans have a very angular Harry. He looks harder somehow.

Q: What plans are being made for Harry Potter, the movie?

A: It's in the very early stages. Summer of 2001 is the target date. I have script approval, and I'm in close contact with the writer.

Among the things that swayed me to Warner Bros. were the movies The Little Princess and The Secret Garden. . . . They treated the books with respect and made changes where it absolutely made sense.

Q: Will there be a TV show?

A: No, I think a film is quite enough. There will be some merchandise with the film. That's the way it goes. If it's stuff kids can play with meaningfully, like dress-up clothes, that's great.

Q: Are you surprised by the number of adults reading Harry Potter?

A: I'm flattered. I wrote these books for me. I wrote what I wanted to read and what I thought I would have liked to read when I was younger.

Q: Do you feel trapped by a seven-book series?

A: Not at all. If I'm always known as a children's writer, that is just fine. . . . And I am utterly resigned to the fact that I probably will never again write books that are this popular. I will always be very, very proud of these books.

Q: Do you think you've changed contemporary literature for children?

A: Three or four publishers turned down Harry Potter for various reasons, but each and every one of them said that it was too long.

I couldn't cut it. There had been several children's books that were 150 pages that were very successful, and that seemed to be what sold. But I've met so many kids on this tour, and, when I tell them that No. 4 will be the longest book yet, they all say, "Yes!"