When Screen-Time Rules Count Homework, Teens Score Lower in Digital Skills

Every parent knows the nightly standoff: the tablet is glowing, the homework tab is open, and somewhere between the math worksheet and the video autoplaying in the next window, screen time becomes impossible to define. A new analysis of nearly 100,000 eighth-graders across 28 education systems suggests that this definitional blur matters more than anyone expected. The study, published in Large-scale Assessments in Education using data from the International Computer and Information Literacy Study (ICILS) 2023, found that the content of a parental screen-time limit — specifically, whether it counts schoolwork — was far more closely tied to adolescents’ tested digital competence than whether a limit existed at all.

The researcher, Jonas Mandalunes, exploited a rarely used survey item that asked students whether their parents limited screen time on school days and, crucially, whether that limit included the time they spent doing schoolwork on a screen. Students fell into three groups: an inclusive limit that treated an hour of homework like an hour of entertainment, an exempt limit that protected schoolwork and restricted only the rest, or no limit at all. Across the 28 systems, a median of 14.8 percent of students reported inclusive limits, 28.3 percent reported exempt limits, and 57.4 percent reported no limits. In other words, among families that set limits at all, roughly two-thirds carved schoolwork out of the daily budget.

The headline result is striking in its consistency. Students whose limits counted schoolwork scored 24.7 points lower in computer and information literacy than students whose limits exempted it, after adjusting for socioeconomic background, gender, home language, and immigrant background. That gap — about 0.30 within-system standard deviations, or roughly 29 percent of the width of a proficiency level — was statistically significant and negative in all 28 education systems, ranging from 48.1 points in Norway to 9.1 points in Oman. The pattern replicated almost perfectly in computational thinking, where the 19 systems that administered that assessment showed a pooled difference of 32.9 points, again negative everywhere.

Just as telling is what the study did not find. Students with no limit scored essentially the same as students with exempt limits in computer and information literacy — a pooled difference of just 0.6 points, small enough to satisfy a formal equivalence test with a margin of ten points. Having a rule, in itself, was not associated with lower competence. The entire penalty was concentrated among the minority of students, roughly one in seven, whose parents counted homework against the clock. This finding reframes the simpler comparison in the official ICILS report, which found students without limits scoring higher in most countries: the study shows mathematically that this binary gap is almost entirely a product of how many inclusive limits a system contains, since the share of inclusive limits among all limits ranged from about one-sixth in Denmark to more than half in Azerbaijan.

The study tested three competing explanations, and none fit alone. The first, an opportunity account, holds that digital skills grow through sustained, purposeful use, so a limit that swallows homework time leaves fewer chances to practice. The second, a displacement account, suggests that counting schoolwork might actually help by curbing the multitasking soup of homework and entertainment on the same device. The third, selection, argues that parents adopt inclusive limits reactively — because a child is struggling, shows weak self-control, or blends homework with play — so the rule marks pre-existing differences rather than causing them.

Several findings point toward selection. Students with inclusive limits came from lower socioeconomic backgrounds in 27 of 28 systems, had less computer experience in 27, expected a university degree less often in 24, and reported lower self-efficacy in 25. The gap shrank steadily as more characteristics were controlled: from 29.8 points without covariates to 24.7 with the basic adjustments, to 22.1 points when age and educational expectations — rough proxies for prior attainment — were added, and to 20.6 points when students were compared only with their own schoolmates. An exploratory meta-regression added a telling gradient: the gap was largest precisely where inclusive limits were rare, shrinking by 0.07 standard deviations for every 10-percentage-point increase in their prevalence. That is the pattern one would expect if an uncommon rule is adopted for specific, child-specific reasons, and harder to explain if the rule itself imposed a fixed cost.

Yet the opportunity account is not dismissed. Students with inclusive limits reported learning internet-related tasks — searching, evaluating sources, spotting scams, managing privacy — less often outside school, where parental rules apply, but not at school, where they do not. That setting-specific pattern is exactly what the opportunity account predicts. They also reported less recreational device use, which may mean fewer occasions for the informal, self-directed exploration through which some digital skills develop. But the simplest version of the story fails: these students reported just as much digital schoolwork at home as their peers, and slightly more long homework sessions. Meanwhile, students with no limits reported the most recreational use and the most multitasking, yet scored like the exempt group in literacy and lower in computational thinking — a reminder that raw hours of screen use track competence poorly.

The author also confronted the elephant in the room: unmeasured confounding. Prior achievement, self-regulation, and parental digital competence are not captured in ICILS, and any of them could shape both the rules families set and the skills students display. A sensitivity analysis following modern omitted-variable methods found that a confounder as strong as the socioeconomic index would shrink the gap only to about 21 points, and one three times as strong would leave roughly 13 points. But the analysis is candid about the limits of that reassurance: prior achievement likely predicts digital competence far better than socioeconomic status does, and a variable that strong would need only a weak link to rule type to account for the entire difference. The 25-point gap, the study stresses, should not be read as the causal effect of a rule.

The methodological care behind these estimates deserves note. The analysis used plausible values, sampling weights, and 75 jackknife replicate weights, pooled system-level estimates through random-effects meta-analysis, and verified the code by reproducing published national averages and the international report’s own limit-versus-no-limit comparison. Results proved robust to reweighting for item nonresponse, to using the parallel non-school-day item, and to adding or excluding individual systems. Students who skipped the rule item scored lower than those who answered it, but inverse-probability reweighting left the conclusions unchanged.

The practical upshot is twofold. For researchers, the message is that surveys of parental mediation must record what a limit covers, not merely whether one exists — studies linking screen rules to achievement, sleep, or wellbeing may otherwise average over rule types whose associations differ in sign and size. For families, the findings align with guidance from the American Academy of Pediatrics and Canadian movement guidelines, which already distinguish recreational from educational screen use, though the study is explicit that it cannot show that changing a rule would change a child’s competence. What it does show is that the one-in-seven students whose parents count homework as screen time differ from their peers in ways the data capture only partly — and that teachers may want to pay attention to exactly those students.

Subject of Research: The relationship between the scope of parental screen-time limits and adolescents' assessed digital competence in ICILS 2023

Article Title: When homework counts as screen time: parental limits and adolescents’ digital competence across 28 education systems in ICILS 2023

Article References: When homework counts as screen time: parental limits and adolescents’ digital competence across 28 education systems in ICILS 2023. (n.d.). https://doi.org/10.1186/s40536-026-00326-6

Image Credits: AI Generated

DOI: 10.1186/s40536-026-00326-6

Keywords: screen time, parental mediation, digital competence, homework, ICILS 2023, computational thinking, computer and information literacy, adolescents, large-scale assessment, meta-analysis, educational technology, parenting