What researchers studied

School-level randomized controlled trial in which 81 Danish schools were randomized and all participating kindergarteners were tested. 2,583 kindergarteners across 81 Danish schools

What they found

  • Decoding improved by 0.38 standard deviations among the preregistered target group.
  • School-wide decoding improved by 0.27 standard deviations.
  • Using bounds based on the test range and random assignment, the authors estimate that never-tutored peers gained at least 0.19 standard deviations, implying a social multiplier of at least three in this setting.
  • Tutors were the schools' own staff.

What the study does not prove

  • This is a 2026 EdWorkingPaper and should not be described as a peer-reviewed journal article unless a later published version is verified.
  • The study concerns early-literacy instruction in Danish kindergarten classrooms and should not be generalized to every subject, age group, country, or private tutoring model.
  • The spillover finding does not establish the exact mechanism by which peers benefited.
  • The result does not mean that every student who receives tutoring will cause measurable gains for classmates.

Evidence strength: Strong experimental evidence; school-level randomized controlled trial; EdWorkingPaper.

Why this matters for families

This study suggests that targeted literacy support can have wider classroom effects in some settings, but it does not prove that all tutoring creates a ripple effect. The safest takeaway is to value learning that becomes usable beyond the tutoring session.

Noor interpretation

How Noor translates the evidence into practice

Learning should be strong enough to travel beyond the supported exercise. The study raises a useful possibility that well-designed instruction can influence explanation, participation, and peer learning beyond the directly tutored student, while the mechanism remains uncertain.

Require students to articulate reasoning, practice independent explanation, and test whether learning transfers when scaffolds are removed. Noor should measure the learner's own transfer rather than promise classroom spillovers.

Read the original source

Noor links to the original or authoritative source so families can distinguish the evidence itself from our interpretation.

Open original source →

DOI: 10.26300/xnz7-3z53

Research notes

early literacytutoringpeer learningrandomized trialdecodingAnnenberg

Revision note: Canonical source corrected to Annenberg EdWorkingPaper 26-1562, DOI 10.26300/xnz7-3z53. Earlier Noor draft creative used an incorrect NBER attribution and must not be used as provenance.

No single study determines a student's plan. Noor uses research as one input alongside the learner's goals, observed performance, academic context, and response to instruction.