The Effectiveness of Volunteer Tutoring Programs: A Meta-Analysis (RCT-only)
Ritter, G. W., Barnett, J. H., Denny, G. S., & Albin, G. R. · 2009
grade Cmeta-analysisindependentreplicated
Sample
21 randomized field trials / 28 cohorts, K-8
Population
US K-8, mostly struggling early-elementary readers.
Design
All-RCT meta of unpaid volunteer tutoring.
Key findings
Structured, supervised volunteer tutoring yields ~0.30 in K-8, concentrated in the exact subskills drilled; math effects undemonstrated. Cheap, but frequency (>=2-3x/week) is non-negotiable.
Genetic confound
Randomized; narrow taught subskills in low-performing samples push d upward.
Replication notes
Consistent with Nickow's nonprofessional range; once-weekly volunteer programs repeatedly fail (incl. Ritter's own RCT).
DOI / URL
10.3102/0034654308325690
Effects
| Outcome | Metric | Value | Measure | Timing | Vs | Horizon | Class |
|---|---|---|---|---|---|---|---|
| Overall achievement | ES | 0.30 | mixed | end of treatment | business-as-usual | end-of-treatment | domain-skill |
| By subskill | ES | letters/words 0.41; writing 0.45; oral fluency 0.30; global reading 0.26; math ns | mixed | end of treatment | business-as-usual | end-of-treatment | domain-skill |
Cited by
- Tutoring — the honest effect, the Bloom 2-sigma myth, and what survives scalestrong supportconf: highgc: low