A brand-new study on the academic effects of homework offers not only some intriguing results but also a lesson on how to read a study -- and a reminder of the importance of doing just that: reading studies (carefully) rather than relying on summaries by journalists or even by the researchers themselves.
Let's start by reviewing what we know from earlier investigations. First, no research has ever found a benefit to assigning homework (of any kind or in any amount) in elementary school. In fact, there isn't even a positive correlation between, on the one hand, having younger children do some homework (vs. none), or more (vs. less), and, on the other hand, any measure of achievement. If we're making 12-year-olds, much less five-year-olds, do homework, it's either because we're misinformed about what the evidence says or because we think kids ought to have to do homework despite what the evidence says.
Second, even at the high school level, the research supporting homework hasn't been particularly persuasive. There does seem to be a correlation between homework and standardized test scores, but (a) it isn't strong, meaning that homework doesn't explain much of the variance in scores, (b) one prominent researcher, Timothy Keith, who did find a solid correlation, returned to the topic a decade later to enter more variables into the equation simultaneously, only to discover that the improved study showed that homework had no effect after all, and (c) at best we're only talking about a correlation -- things that go together -- without having proved that doing more homework causes test scores to go up. (Take 10 seconds to see if you can come up with other variables that might be driving both of these things.)
Third, when homework is related to test scores, the connection tends to be strongest -- or, actually, least tenuous -- with math. If homework turns out to be unnecessary for students to succeed in that subject, it's probably unnecessary everywhere.
Along comes a new study, then, that focuses on the neighborhood where you'd be most likely to find a positive effect if one was there to be found: math and science homework in high school. Like most recent studies, this one by Adam Maltese and his colleagues doesn't provide rich descriptive analyses of what students and teachers are doing. Rather, it offers an aerial view, the kind preferred by economists, relying on two large datasets (from the National Education Longitudinal Study [NELS] and the Education Longitudinal Study [ELS]). Thousands of students are asked one question -- How much time do you spend on homework? -- and statistical tests are then performed to discover if there's a relationship between that number and how they fared in their classes and on standardized tests.
It's easy to miss one interesting result in this study that appears in a one-sentence aside. When kids in these two similar datasets were asked how much time they spent on math homework each day, those in the NELS study said 37 minutes, whereas those in the ELS study said 60 minutes. There's no good reason for such a striking discrepancy, nor do the authors offer any explanation. They just move right along -- even though those estimates raise troubling questions about the whole project, and about all homework studies that are based on self-report. Which number is more accurate? Or are both of them way off? There's no way of knowing. And because all the conclusions are tied to that number, all the conclusions may be completely invalid.
But let's pretend that we really do know how much homework students do. Did doing it make any difference? The Maltese et al. study looked at the effect on test scores and on grades. They emphasized the latter, but let's get the former out of the way first.
Was there a correlation between the amount of homework that high school students reported doing and their scores on standardized math and science tests? Yes, and it was statistically significant but "very modest": Even assuming the existence of a causal relationship, which is by no means clear, one or two hours' worth of homework every day buys you two or three points on a test. Is that really worth the frustration, exhaustion, family conflict, loss of time for other activities, and potential diminution of interest in learning? And how meaningful a measure were those tests in the first place, since, as the authors concede, they're timed measures of mostly mechanical skills? (Thus, a headline that reads "Study finds homework boosts achievement" can be translated as "A relentless regimen of after-school drill-and-skill can raise scores a wee bit on tests of rote learning.")
But it was grades, not tests, that Maltese and his colleagues really cared about. They were proud of having looked at transcript data in order to figure out "the exact grade a student received in each class [that he or she] completed" so they could compare that to how much homework the student did. Previous research has looked only at students' overall grade-point averages.
And the result of this fine-tuned investigation? There was no relationship whatsoever between time spent on homework and course grade, and "no substantive difference in grades between students who complete homework and those who do not."
This result clearly caught the researchers off-guard. Frankly, it surprised me, too. When you measure "achievement" in terms of grades, you expect to see a positive result -- not because homework is academically beneficial but because the same teacher who gives the assignments evaluates the students who complete them, and the final grade is often based at least partly on whether, and to what extent, students did the homework. Even if homework were a complete waste of time, how could it not be positively related to course grades?
And yet it wasn't. Again. Even in high school. Even in math. The study zeroed in on specific course grades, which represents a methodological improvement, and the moral may be: The better the research, the less likely one is to find any benefits from homework. (That's not a surprising proposition for a careful reader of reports in this field. We got a hint of that from Timothy Keith's reanalysis and also from the fact that longer homework studies tend to find less of an effect.)
Maltese and his colleagues did their best to reframe these results to minimize the stunning implications. Like others in this field, they seem to have approached the topic already convinced that homework is necessary and potentially beneficial, so the only question we should ask is How -- not whether -- to assign it. But if you read the results rather than just the authors' spin on them -- which you really need to do with the work of others working in this field as well -- you'll find that there's not much to prop up the belief that students must be made to work a second shift after they get home from school. The assumption that teachers are just assigning homework badly, that we'd start to see meaningful results if only it were improved, is harder and harder to justify with each study that's published.
If experience is any guide, however, many people will respond to these results by repeating platitudes about the importance of practice, or by complaining that anyone who doesn't think kids need homework is coddling them and failing to prepare them for the "real world" (read: the pointless tasks they'll be forced to do after they leave school). Those open to evidence, however, have been presented this Fall with yet another finding that fails to find any meaningful benefit even when the study is set up to give homework every benefit of the doubt.
1. It's important to remember that some people object to homework for reasons that aren't related to the dispute about whether research might show that homework provides academic benefits. They argue that (a) six hours a day of academics are enough, and kids should have the chance after school to explore other interests and develop in other ways -- or be able simply to relax in the same way that most adults like to relax after work; and (b) the decision about what kids do during family time should be made by families, not schools. Let's put these arguments aside for now, even though they ought to be (but rarely are) included in any discussion of the topic.
2. Valerie A. Cool and Timothy Z. Keith, "Testing a Model of School Learning: Direct and Indirect Effects on Academic Achievement," Contemporary Educational Psychology 16 (1991): 28-44.
3. Adam V. Maltese, Robert H. Tai, and Xitao Fan, "When Is Homework Worth the Time? Evaluating the Association Between Homework and Achievement in High School Science and Math," The High School Journal, October/November 2012: 52-72. Abstract at http://ow.ly/fxhOV.
4. Other research has found little or no correlation between how much homework students report doing and how much homework their parents say they do. When you use the parents' estimates, the correlation between homework and achievement disappears. See Harris Cooper, Jorgianne Civey Robinson, and Erika A. Patall, "Does Homework Improve Academic Achievement?: A Synthesis of Research, 1987-2003," Review of Educational Research 76 (2006): 1-62.
5. To put it the other way around, studies finding the biggest effect are those that capture less of what goes on in the real world by virtue of being so brief. View a small, unrepresentative slice of a child's life and it may appear that homework makes a contribution to achievement; keep watching, and that contribution is eventually revealed to be illusory. See data provided -- but not interpreted this way -- by Cooper, The Battle Over Homework, 2nd ed. (Thousand Oaks, CA: Corwin, 2001).
6. Even the title of their article reflects this: They ask "When Is Homework Worth the Time?" rather than "Is Homework Worth the Time?" This bias might seem a bit surprising in the case of the study's second author, Robert H. Tai. He had contributed earlier to another study whose results similarly ended up raising questions about the value of homework. Students enrolled in college physics courses were surveyed to determine whether any features of their high school physics courses were now of use to them. At first a very small relationship was found between the amount of homework that students had had in high school and how well they were currently faring. But once the researchers controlled for other variables, such as the type of classes they had taken, that relationship disappeared, just as it had for Keith (see note 2). The researchers then studied a much larger population of students in college science classes - and found the same thing: Homework simply didn't help. See Philip M. Sadler and Robert H. Tai, "Success in Introductory College Physics: The Role of High School Preparation," Science Education 85 : 111-36.
7. See chapter 4 ("'Studies Show...' -- Or Do They?") of my book The Homework Myth (Cambridge, MA: Da Capo, 2006), an adaptation of which appears as "Abusing Research: The Study of Homework and Other Examples," Phi Delta Kappan, September 2006 .
8. On the alleged value of practice, see The Homework Myth, pp. 106-18, also available at http://bit.ly/9dXqCj.
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From kindergarten to the final years of high school, recent research suggests that some students are getting excessive amounts of homework.
In turn, when students are pushed to handle a workload that’s out of sync with their development level, it can lead to significant stress — for children and their parents.
Both the National Education Association (NEA) and the National PTA (NPTA) support a standard of “10 minutes of homework per grade level” and setting a general limit on after-school studying.
For kids in first grade, that means 10 minutes a night, while high school seniors could get two hours of work per night.
But the most recent study to examine the issue found that kids in early elementary school received about three times the amount of recommended homework.
Published in The American Journal of Family Therapy, the 2015 study surveyed more than 1,100 parents in Rhode Island with school-age children.
The researchers found that first and second graders received 28 and 29 minutes of homework per night.
Kindergarteners received 25 minutes of homework per night, on average. But according to the standards set by the NEA and NPTA, they shouldn’t receive any at all.
A contributing editor of the study, Stephanie Donaldson-Pressman, told CNN that she found it “absolutely shocking” to learn that kindergarteners had that much homework.
And all those extra assignments may lead to family stress, especially when parents with limited education aren’t confident in their ability to help kids with the work.
The researchers reported that family fights about homework were 200 percent more likely when parents didn’t have a college degree.
Some parents, in fact, have decided to opt out of the whole thing. The Washington Post reported in 2016 that some parents have just instructed their younger children not to do their homework assignments.
They report the no-homework policy has taken the stress out of their afternoons and evenings. In addition, it's been easier for their children to participate in after-school activities.
This new parental directive may be healthier for children, too.
Experts say there may be real downsides for young kids who are pushed to do more homework than the “10 minutes per grade” standard.
“The data shows that homework over this level is not only not beneficial to children’s grades or GPA, but there’s really a plethora of evidence that it’s detrimental to their attitude about school, their grades, their self-confidence, their social skills, and their quality of life,” Donaldson-Pressman told CNN.
Read more: Less math and science homework beneficial to middle school students »
Consequences for high school students
Other studies have found that high school students may also be overburdened with homework — so much that it’s taking a toll on their health.
In 2013, research conducted at Stanford University found that students in high-achieving communities who spend too much time on homework experience more stress, physical health problems, a lack of balance in their lives, and alienation from society.
That study, published in The Journal of Experimental Education, suggested that any more than two hours of homework per night is counterproductive.
However, students who participated in the study reported doing slightly more than three hours of homework each night, on average.
To conduct the study, researchers surveyed more than 4,300 students at 10 high-performing high schools in upper middle-class California communities. They also interviewed students about their views on homework.
When it came to stress, more than 70 percent of students said they were “often or always stressed over schoolwork,” with 56 percent listing homework as a primary stressor. Less than 1 percent of the students said homework was not a stressor.
The researchers asked students whether they experienced physical symptoms of stress, such as headaches, exhaustion, sleep deprivation, weight loss, and stomach problems.
More than 80 percent of students reported having at least one stress-related symptom in the past month, and 44 percent said they had experienced three or more symptoms.
The researchers also found that spending too much time on homework meant that students were not meeting their developmental needs or cultivating other critical life skills. Students were more likely to forgo activities, stop seeing friends or family, and not participate in hobbies.
Many students felt forced or obligated to choose homework over developing other talents or skills.
"Our findings on the effects of homework challenge the traditional assumption that homework is inherently good," said Denise Pope, Ph.D., a senior lecturer at the Stanford University School of Education, and a co-author of a study.
Read more: Should schools screen children for mental health problems? »
Working as hard as adults
A smaller New York University study published last year noted similar findings.
It focused more broadly on how students at elite private high schools cope with the combined pressures of school work, college applications, extracurricular activities, and parents’ expectations.
That study, which appeared in Frontiers in Psychology, noted serious health effects for high schoolers, such as chronic stress, emotional exhaustion, and alcohol and drug use.
The research involved a series of interviews with students, teachers, and administrators, as well as a survey of a total of 128 juniors from two private high schools.
About half of the students said they received at least three hours of homework per night. They also faced pressure to take college-level classes and excel in activities outside of school.
Many students felt they were being asked to work as hard as adults, and noted that their workload seemed inappropriate for their development level. They reported having little time for relaxing or creative activities.
More than two-thirds of students said they used alcohol and drugs, primarily marijuana, to cope with stress.
The researchers expressed concern that students at high-pressure high schools can get burned out before they even get to college.
“School, homework, extracurricular activities, sleep, repeat — that’s what it can be for some of these students,” said Noelle Leonard, Ph.D., a senior research scientist at the New York University College of Nursing, and lead study author, in a press release.
Read more: Lack of mental healthcare for children reaches ‘crisis’ level »
What can be done?
Experts continue to debate the benefits and drawbacks of homework.
But according to an article published this year in Monitor on Psychology, there’s one thing they agree on: the quality of homework assignments matters.
In the Stanford study, many students said that they often did homework they saw as "pointless" or "mindless."
Pope, who co-authored that study, argued that homework assignments should have a purpose and benefit, and should be designed to cultivate learning and development.
It’s also important for schools and teachers to stick to the 10-minutes per grade standard.
In an interview with Monitor on Psychology, Pope pointed out that students can learn challenging skills even when less homework is assigned.
Pope described one teacher she worked with who taught advanced placement biology, and experimented by dramatically cutting down homework assignments. First the teacher cut homework by a third, and then cut the assignments in half.
The students’ test scores didn’t change.
“You can have a rigorous course and not have a crazy homework load,” Pope said.
Editor’s Note: The story was originally published on March 11, 2014. It was updated by Jenna Flannigan on August 11, 2016 and then updated again on April 11, 2017 by David Mills.