Bibliographic Data
Tutors are increasingly central to school-based instruction, with the potential to personalize learning at scale. Little is known about which tutor characteristics predict effectiveness, limiting providers' and schools' recruiting, hiring, and retention strategies. Using random assignment of tutors in a high-dosage elementary-grade online literacy tutoring program, we examine how literacy development relates to demographic congruence and tutor preparation, experience, and demographic and cultural characteristics. Contrary to the teacher-student match research, we do not find that Black students benefit uniquely from assignment to Black tutors. Neither bachelor's degrees nor classroom teaching experience predicts superior gains. Instead, experience with the same provider is associated with 0.2 SD greater literacy growth, underscoring the importance of tutor development and retention for large-scale programs.