When Lily Shum was little, she dreaded speaking up in class. It wasn't because she didn't have anything interesting to say, or because she wasn't paying attention or didn't know the answer. She was just quiet.

"Every single report card that I ever had says, 'Lily needs to talk more. She is too quiet,' " recalls Shum, now an assistant director at Trevor Day School in Manhattan.

She doesn't want her students to feel the pressure to speak up that she felt.

That's why she's joined more than 60 educators in New York City recently at the Quiet Summer Institute. The professional development workshop was based on Susan Cain's bestseller Quiet: The Power of Introverts In A World That Can't Stop Talking.

The book has been a national phenomenon, and it's the inspiration behind a curriculum developed by Heidi Kasevich for teachers.

"It was a lens through which I could view my entire life, and really feel the license to be myself," says Kasevich, a teacher for more than 20 years who now works for the company Cain co-founded to promote the book's message about introverts.

This training workshop uses this book — and Cain's latest book written for middle-schoolers — to help teachers notice, and serve, those quiet kids.

"There are expectations on our kids to ... be a charismatic extrovert," says Kasevich. Even if it's unconscious, she says, teachers tend to give more attention to the louder students.

Kasevich admits she did it too: calling on the kids who raised their hands first.

The two-day course started with re-imagining class participation, which in some schools can count for a big portion of students' grades. Kasevich would prefer it be called classroom engagement.

"Being present and connecting doesn't have to take place through lots of speech," she says. Why not try drawing, writing or working in pairs?

Or, Kasevich suggests, have students walk around the room, writing ideas on tacked up pieces of paper. They can respond to each other's ideas — like a sort of silent dialogue.

Educators at the summit heard from Cain herself and also Amy Cuddy and Priscilla Gilman — writers who've touched on the subject of introverts.

Principals and administrators mixed with school psychologists, guidance counselors and teachers. They met in small groups to discuss ideas and tips.

At one session, Erica Corbin, the director of community life and diversity at a private girls' school in Manhattan, told her team that focusing on introverts also means reining in the extroverts.

She offered up this tip for handling students who dominate the discussion: W-A-I-T. Sure, it means wait. But, Corbin explains, it also stands for: "Why Am I Talking?"

Below The Surface

With shy kids, says Corbin, it's not just about paying attention to them. Teachers need to think about why they're quiet.

"Personality might be some of it," she explains, "and we also might have kids who are quiet because they have been shut down. We might have kids that are quiet because they anticipate being shut down whether they have been or not."

Shutting down for all kinds of reasons, she adds. Stereotypes. Biases. Trouble at home: "When we're thinking about students who are quiet, how does that also connect with their race ... their gender ... their sexuality?"

Copyright 2016 NPR. To see more, visit http://www.npr.org/.