The effect of student-tutor ratios: Experimental evidence from a pilot online math tutoring program

Budget constraints and limited tutor supply have caused many K-12 school districts to pivot from individual tutoring toward small-group tutoring to expand access to personalized instruction. We conduct a pilot experiment to contrast the effects of student-tutor ratios on middle school students’ math achievement and growth during an online tutoring program. We leverage a novel feature of the program where tutors often taught individual and small-group tutoring sessions, allowing them to directly compare their experiences across these settings. Both experimental estimates and tutor survey responses provide suggestive evidence that 1:1 tutoring is more effective than 3:1 tutoring in an online setting. Tutoring small groups online presents additional challenges for personalizing instruction, developing relationships, fostering participation, and managing student behavior.