A new study by Stanford researchers Hsiaolin Hsieh, David Gormley, Carly D. Robinson, and Susanna Loeb suggests why one-on-one tutoring has been found to produce double the gains in student learning than two-on-one tutoring.
Analyzing 16,629 transcripts from 2022-23 school year tutoring sessions from an earlier study that established the greater gains under one-on-one tutoring, the researchers examined how tutors allocated their time and attention across both one-on-one and two-on-one formats. The tutoring sessions focused on early literacy and served kindergarten through second grade students, with 510 students receiving one-on-one tutoring and 570 students receiving two-on-one tutoring. All students met with their tutor online for 20 minutes during the school day, four times per week.
The researchers found that while tutors in both formats dedicated similar amounts of time to instruction and relationship building, students in two-on-one sessions received less individualized attention. Tutors alternated between addressing both students together and focusing on one at a time, reducing targeted support, which the researchers note can increase student disengagement and limit learning gains. Tutors in two-on-one settings also spent 63 percent more time managing behavior and transitions, further increasing the likelihood of student disengagement.
By contrast, tutors in one-on-one sessions were more likely to use motivational praise, make personal connections, and engage playfully, strategies that can build stronger relationships and sustain student engagement. Despite these differences, the study finds that tutors in both formats expressed similar levels of care and affection toward their students.
Given the financial constraints many schools face, the researchers note that two-on-one tutoring is likely to become more common as a more affordable alternative to one-on-one tutoring. They emphasize strengthening this model by equipping tutors with strategies to actively engage both students simultaneously, reducing downtime and the risk of disengagement, and ultimately boosting learning gains.