The number of students disciplined in schools across Massachusetts declined 20 percent last year, a dramatic drop that follows a change in the way all school districts are required to approach punishment.
In all, 10,000 fewer students were disciplined during the 2014-15 school year, according to state data released this week.
Disciplinary measures are defined as expulsion, out-of-school suspension, and in-school suspension. They are imposed on students who break any of a long list of infractions, such as unruly behavior, skipping school, fighting, bringing drugs or a weapon to school, or assaulting a teacher.
Education officials heralded the decline as proof that schools are following a new state law that aims to reduce long-term suspensions — defined as more than 10 days — and ensure that punished students don't miss lessons.
A growing body of research suggests that students who are suspended repeatedly are more likely to fall behind academically and drop out.
Although the rate of overall discipline has dropped, it remains uneven in some school-to-school comparisons. Black, Latino, and poor students continue to receive out-of-school suspensions at higher rates than their white classmates.
But education advocates were heartened by the fact that discipline rates for those students declined faster than the state average.
"To see across-the-board drops by race, disability, and language-learner status is a positive step forward for our state," said Matt Cregor, a staff attorney for the Lawyers' Committee for Civil Rights and Economic Justice, a nonpartisan legal organization in Boston that published a report last year about school discipline.
The new data show the rate of out-of-school suspensions, which essentially means students are sent home for a day or more, dropped to 2.9 percent in 2014-15, down from 3.9 percent in the previous school year. The report does not show the length of the suspensions.
Overall, Boston public schools disciplined about 5 percent of their 58,000 students last year, data show, down from about 6 percent the year before.
State officials hope the reduction in discipline creates a better atmosphere in schools and a "more positive interventions and supports for students," Lauren Greene, the assistant chief of staff at the Department of Elementary and Secondary Education, said in a statement Wednesday.
Instead of suspending students, many schools have tried to work with them in the classroom, use peer mediation, small group instruction, one-on-one counseling and provide extra help for teachers.
"While we never want to limit a school from having the power to intervene in a serious situation, in some cases an alternative or additional services may have a greater impact on changing a student's behavior," Greene said.
While black students are sent to out-of-school suspension at higher rates (6.9 percent last year) those figures are dropping faster than the statewide rate — down from 9.3 percent in the year prior, data show.
The same is true for Latino students, 5.6 percent of whom were sent home last year, compared with 7.7 percent the year prior.
Charter schools have some of the highest discipline rates. But the data suggest that they are also using alternatives to suspension.
Roxbury Preparatory Charter, City on a Hill Charter in Dudley Square, and City on a Hill Charter in New Bedford had the highest rates of out-of-school suspension statewide — between 35 percent and 40 percent. But those percentages were slightly lower than rates at those schools the year before.
A spokesman for the Massachusetts Charter Public School Association said Wednesday that higher discipline rates at charter schools in Boston do not correlate with higher dropout or attrition rates.
"Charters have traditionally had higher standards for classroom behavior and have employed out-of-school suspension to maintain an environment in the classroom that's conducive to learning," said the spokesman, Dominic Slowey.
The Boston public school district is implementing measures to take before a student has to be suspended, a School Department spokesman said.
"Providing students in-school supports for social emotional well-being and academic success is a primary focus,'' Dan O'Brien, press secretary for department, said.
While heartened by the new report, Cregor, of the Lawyers' Committee for Civil Rights and Economic Justice, said he worries that schools are underreporting discipline, especially emergency removals. That is when a principal removes a student temporarily after he or she is charged with a disciplinary offense because the principal believes the student is dangerous.
"I'm worried about the kids whose schools are maybe saying, 'Why don't you take a cool-down, stay home for a couple of days, we won't put it on your record,' " Cregor said.
Laura Krantz can be reached at email@example.com.