Large schools like the 3,000-student William R. Boone High School in Orlando, Fla., try to enforce a one-time-per-person rule for candid photos and quotations, but nine slipped in twice last year. “I do not let them forget that,” said Renee Burke, the yearbook adviser. “That’s nine kids that didn’t get in because these nine were there twice.”

In California, the 32 students on the yearbook staff at Whitney High School in Rocklin routinely use e-mail, surveys and a Facebook page to find out about people and events they might not otherwise cover; as much as one-fifth of the yearbook’s content now comes from reader suggestions.

The changing yearbook is a result of a decades-old effort to foster a kinder, gentler culture through measures like smaller schools, character-building and peer counseling. “We want every student to be known and valued in a school,” said Mel Riddile, associate director for high school services for the National Association of Secondary School Principals, adding that research has shown that students are less likely to drop out when they feel connected to their school.

Rosalind Wiseman, author of the best-selling book “Queen Bees and Wannabes” (Crown, 2002), which inspired the movie “Mean Girls,” said a more inclusive yearbook not only benefited less-popular students, but also taught the students in charge of the yearbook to look through a broader lens. “They need to sit at the table and figure it out,” she said. “They need to say, ‘Hey, that person’s been in 20 times, forget it.’ These are all very important social skills to develop.”

Some have questioned whether yearbooks go too far when they try to give everyone equal coverage, regardless of how much  or how little  a student contributes to school life.

“It’s unfair to suggest that everyone should get equal time when they haven’t put in equal time,” said Jean Twenge, a psychology professor at San Diego State University and the author of “Generation Me” (Free Press, 2006). “Having everyone get equal time is the equivalent of everyone gets a trophy, or we’re not going to keep score, or even if we do, everyone’s trophy is the same size. There’s no resemblance to real life.”