What the research found

Grade or subject Finding Source
Preschool to 1st grade One-on-one beat pairs and small groups: 0.51 SD in preschool and kindergarten, 0.44 SD in 1st grade J-PAL, summarizing the 2020 meta-analysis
Grades 2–5 Groups of three or more did better (0.46 SD) than one-on-one (0.25 SD) J-PAL
All grades, teachers and paraprofessionals as tutors One-on-one had the largest effects, but larger groups were statistically similar; the authors say grade level mattered more than group size Nickow, Oreopoulos and Quan
All grades, a 2024 review 0.43 SD for one-on-one, 0.41 for pairs, 0.30 for groups of three and 0.34 for groups of four, with no statistically significant differences Kraft, Schueler and Falken
Reading One-on-one produces greater gains than small groups on average, in elementary and secondary grades EdResearch brief, 2024
Elementary math Small groups can produce equal or better results than one-on-one Same brief

The National Student Support Accelerator sums it up as one-on-one being the most effective format but also the most costly, with groups of no more than three balancing effectiveness and cost (toolkit). Its pages put the upper limit at three or four students per tutor.

Experiments that compared group sizes

  • 1st-grade reading: in a 2012 study, 85 Reading Recovery teachers each taught struggling 1st graders both one-on-one and in groups of 2, 3 or 5. One-on-one produced significantly higher results than the small groups combined on 8 of 9 measures, and results trended lower as groups grew (study summary).
  • Kindergarten math: in a randomized trial of the ROOTS math program, children taught in groups of two didn't do measurably better than children taught in groups of five (Clarke and others, 2017).
  • Online middle school math: in a small study, one-on-one online tutoring outscored groups of three, though the difference wasn't statistically significant, and tutors said small online groups made it harder to personalize, build relationships and keep everyone participating (Kraft and Lovison, 2024).

Which fits your child

One-on-one fits better A small group of 2–4 fits well
A kindergartner or 1st grader learning to read Elementary math practice, where explaining to each other helps
A child who is far behind, or whose gaps are unusual Two or three friends or siblings at a similar level
A child who goes quiet or drifts in a group A child who works harder with a peer
Online sessions, where groups are harder to run A fixed budget for more sessions per week

A group only works if the children are close in level and working on the same skills. If a group spans very different levels, everyone gets less.

Prices

Thousand Acorns Tutoring teaches small groups of 2 to 4 children at $50 an hour per child, compared with $80 an hour in your home or online one-on-one. Among local providers that publish both, Oaks Christian Learning Center in Westlake Village lists $80 for a 60-minute one-on-one session and $60 per session for two students with one tutor (Oaks Christian, opened October 13, 2026). More local prices are in what tutoring costs in Thousand Oaks.

Questions parents ask

Is one-on-one tutoring better than a small group?

For kindergarten and 1st-grade readers, one-on-one has the stronger evidence. For grades 2–5, the 2020 meta-analysis found groups of three or more did as well or better, and a 2024 review found no statistically significant difference between one-on-one and groups of two to four.

What is a good tutoring group size?

Research summaries describe the most effective programs as having no more than three students per tutor, and Stanford's National Student Support Accelerator found only small differences between groups of two and four. Thousand Acorns Tutoring's small groups are 2 to 4 children.

Does a small group work for reading?

For beginning readers, one-on-one is usually stronger: in one randomized study of struggling 1st-grade readers, one-on-one beat the small groups (sizes 2, 3 and 5 combined) on 8 of 9 measures. Once a child is reading, a small group can work well for comprehension and writing.

How much cheaper is small-group tutoring?

It depends on the provider. Thousand Acorns Tutoring charges per child for groups. Locally, Oaks Christian Learning Center publishes $80 for a 60-minute one-on-one session and $60 per session for two students with one tutor.

Sources