Private tutoring and supplemental learning are intended to enhance classroom learning, but new research led by a professor in the Penn State College of Education has revealed that it may actually erode student engagement. The finding came from an analysis of South Korean elementary students but has global implications, the researchers said.
In a paper recently published in Comparative Education Review, Soo-yong Byun, professor of education, of demography and of Asian studies and Social Science Research Institute cofunded faculty member, found that South Korean elementary students who consistently participate in private tutoring are more likely to become behaviorally disengaged at school. The researchers analyzed nationally representative data for South Korean elementary school students, comprising academic achievement, participation in private tutoring and engagement measures, among other information. They found that students engaged in what’s known as “shadow education” during both fifth and sixth grades — the final two years of elementary school in South Korea, during which students are typically 10 to 12 years old — exhibited notably higher levels of classroom disengagement such as daydreaming and sleeping during lessons.
“Policymakers in Korea have long worried that extensive private tutoring might harm students’ well-being and interest in school because fatigue resulting from long hours spent in private tutoring may undermine students’ ability to actively engage in their regular classroom learning,” Byun said. “Our study is one of the first to provide empirical evidence that these concerns are real.”
Byun and his co-authors used data from the Korean Education Longitudinal Study of 2013, which tracks a nationally representative sample of over 7,000 fifth grade students over time. Specifically, the researchers focused on data from fifth and sixth grade students across two consecutive years.
The survey data included information about behavioral disengagement using a validated scale that asked students how often they felt bored, distracted or unwilling to participate in classroom activities. Participation in shadow education was assessed by whether students reported attending any form of private tutoring — including one-on-one lessons, small group sessions or large cram schools, which are private educational institutions that provide intensive tutoring and preparation for exams, typically to help students improve their academic performance or test scores — in both grades.
Using a statistical approach called multiple regression analysis, the researchers controlled for a wide range of factors, including students’ prior engagement levels, socioeconomic status, academic achievement, and various family and school characteristics. This allowed the researchers to isolate the unique effect of sustained shadow education on later behavioral disengagement.
They found that students engaged in shadow education in both fifth and sixth grade had slightly higher behavioral disengagement scores than peers who did not participate, even after accounting for other influences.
“This impact might seem small, but it’s a meaningful difference when we think about the effect sizes of other school interventions and its practical implications for millions of students,” Byun said.
In South Korea, over 80% of students participate in some form of private tutoring, fueling significant family expenditures and deepening educational inequality. Wealthier families can afford extensive private lessons, while lower-income families struggle to keep up, creating gaps in both achievement and engagement, Byun said.
Although the United States has not reached the same saturation levels, Byun cautioned that the trends are moving in a similar direction.
“We’re seeing more American parents invest in private academic tutoring or enrichment programs outside school hours,” he said. “While it’s not yet a widespread social issue like in Korea, there’s potential for similar challenges.”
Byun said the findings carry implications for U.S. policymakers, particularly as states continue to emphasize standardized testing and accountability systems. Increased academic pressure can drive families to seek out private tutoring, potentially creating unintended consequences for classroom engagement and mental health.
“Many U.S. policymakers view tutoring as a way to help disadvantaged students catch up academically,” Byun said, explaining that interventions aimed at helping students could potentially undermine a student’s school experience. “But my research shows that heavy reliance on private tutoring may actually harm students’ connection to their regular classes, even if it may improve test scores.”
One of the thorniest issues for governments, according to Byun, is how to regulate an inherently private industry. In the U.S., as in Korea, most private tutoring remains outside government oversight, making it difficult to ensure equitable access or to mitigate its potentially negative effects.
“There’s very little the government can directly control in the private sector,” Byun noted. “But one approach is for schools to provide high-quality after-school programs, reducing socioeconomic disparities in out-of-school learning opportunities.”
Byun emphasized that teachers and school administrators can also play a key role in mitigating disengagement.
“Educators should pay close attention to students who rely heavily on private tutoring and who might be more disengaged in class,” he said. “Otherwise, their disengagement can affect the classroom climate and other students.”
Byun said he believes there’s an urgent need for international dialogue on the consequences of shadow education. He has collaborated with researchers in Germany and Japan and noted that organizations like UNESCO are increasingly focusing on the global rise of private supplementary education.
“What began as a regional issue in East Asia has become a worldwide phenomenon,” he said. “We need more research and policy discussion to ensure that education systems promote equity and keep students engaged — not just academically, but emotionally and behaviorally as well.”
Byun’s co-authors on the paper are Suyoung Park, a doctoral student in educational theory and policy at Penn State; Hee Jin Chung, a lecturer member at Korea National University of Education in South Korea who received a doctorate in educational theory and policy at Penn State in 2018; Jilli Jung, a postdoctoral researcher at Stanford University who received a doctorate in educational theory and policy from Penn State in 2024; Tae Seob Shin, a faculty member at Ewha Womans University in South Korea; and Jieon Kim, an associate professor at Monmouth University.