Seemingly minor classroom disruptions—like intercom announcements and students’ late arrivals—can add up to hours of lost instructional time each year, exacerbating already stark differences across the country in how much time kids spend learning, according to a new study.
There’s no national policy dictating how many days or hours students must attend classes each year. That’s a decision left to state lawmakers, which has, in turn, led to significant variation depending on where a child attends school.
The states that require the most instructional time in effect mandate the equivalent of about 1.5 academic years more of school over the course of a student’s K-12 career than those with the lightest requirements, according to the study, which is the result of researchers examining 74 studies related to instructional time and student achievement as well as class time requirements in each state.
The average U.S. student spends 1,231 hours in school each year. But in the five states that require the most instructional time—Texas, Nebraska, Arkansas, Mississippi, and Alabama—students spend at least 1,300 hours per year in class. Students in Hawaii, Nevada, Maine, Oregon, and Rhode Island—the five states on the other end of the spectrum—are in school for fewer than 1,150 hours each year. That’s 150 fewer hours each year.
Over the course of a 13-year academic career, that adds up to 1,950 fewer hours in class—the equivalent of at least one-and-a-half school years.
But not all classroom time is created equal. Even when their states have steep classroom time requirements, schools may be losing hundreds of hours of instruction each year to minor, avoidable disturbances and teacher absences, according to the researchers.
“There’s a huge gap between legislating the amount of time the kids should be in school and the actual amount of instruction that students get that’s meaningful and high quality,” said Matthew Kraft, an associate professor at Brown University, who co-authored the study with Sarah Novicoff, a doctoral candidate at Stanford University. “We have incredible work to do to bridge that gap.”
The new analysis, which appeared in the journal Education Next, comes a time when schools continue to grapple with declines in academic achievement stemming from pandemic closures. And while research shows more time in school generally correlates with higher achievement, schools have also experienced high rates of chronic absenteeism since reopening their buildings, translating into significant instructional time losses. In addition, more districts in recent years—though still a small number—have switched to four-day schedules to try and beat teacher burnout and cut costs, although recent research suggests the truncated schedules may not have the intended outcomes.
While America’s students are unnecessarily losing valuable learning time, the researchers outlines a few strategies schools can use to maximize school time.
States vary widely in their classroom time requirements
Sixteen states set both the minimum length of the school year in days and hours, while 10 states give districts the freedom to meet either a minimum number of days or total hours. Eleven states require only a minimum number of days without specifying the length of the day, and 13 states only set a minimum number of total hours, according to 2023 data from the Education Commission of the States.
The differences become even more apparent, though, when looking at the actual mandates in each state.
Among the 37 states that identify a minimum number of days each year, 28 set it at 180 days. At the low end of the spectrum, Colorado requires 160 days while Kansas mandates 186.
Thirty-nine states specify a minimum number of hours, with similarly wide variation. For example, high school students in Arizona must spend at least 720 hours at school each year, while high schoolers in Texas must spend at least 1,260 hours in class, according to the analysis.
Within states, there are instructional time differences by district.
Suburban schools have the shortest sessions, on average, at 1,212 hours per year, compared with roughly 1,240 hours per year at schools in cities, towns, and rural areas, Kraft and Novicoff found from reviewing the federal government’s National Teacher and Principal Survey. Charter schools are also in session longer than traditional public schools: 1,291 hours compared with 1,226 on average.
And Black students and students who qualify for free and reduced-price lunch are disproportionately more likely than other student groups to attend schools that offer the most instructional time.
The additional hours are only valuable, however, if they are used intentionally, said Kraft. The most “substantial impacts” from additional class time happened at schools that had taken other steps to improve achievement, such as tutoring, increased school spending, and the replacement of underperforming staff.
“We find compelling evidence that more time benefits students, although, of course, how that time is used is paramount, and it doesn’t always mean that it’s guaranteed to be beneficial,” Kraft said. “We have to be thoughtful about when it’s added and what it’s used for.”
Minor daily interruptions to class time add up
To illustrate the amount of instructional time schools can lose each day to minor interruptions, Kraft and Novicoff examined how schools in Providence, R.I., spend their time. They chose Providence because its schools had high student absence rates prior to the pandemic.
They found that high schools in Providence are in session for 6.75 hours per day, and all but about one hour of that is instructional time. However, the average student lost a quarter of their daily instructional time, most of it to unexcused student absences, outside interruptions like intercom announcements, and teacher absences.
They found similar trends in the district’s middle and elementary schools, where students lost about 21 percent and 16 percent of instructional time, respectively.
Interruptions and teacher absences cost the average Providence high school student about 97 hours of instructional time each year, according to the research.
Both of those factors are “arguably under the direct control of school districts, which could minimize intercom interruptions, incentivize teacher attendance, and build deeper pools of substitute teachers,” the study said.
Districts should ‘fiercely avoid reducing time in school’
While encouraging states with the lightest learning time requirements to boost their minimum times to align with national averages is at the top of Novicoff’s and Kraft’s list of recommendations, they acknowledged it can be tough to get enough support to pull it off.
“At a minimum, districts should fiercely avoid reducing time in school,” the pair said in their study. They advise against moving to four-day weeks or cutting the amount of required hours.
Schools should also invest in initiatives to reduce student and teacher absences, they said.
In addition, schools could also make low- or no-cost adjustments by focusing on not “interrupting class wherever possible,” the study said. Instead of using an intercom to make non-emergency announcements during class, schools should only use it during passing periods, and administrators should visit in person or send emails to communicate en masse with staff, the researchers said.
“Things like that, that may seem really small, add up over the course of a class period, because when an intercom rings, sure, the intercom announcement itself is only 30 seconds long, but the teacher can take much more time than that to get back on track,” Novicoff said.
Kraft added: “There’s opportunities, even keeping the exact schedule you have now, to plug those holes of where that time trickles out of the system and is lost and more meaningfully support the students.”
