High Dosage Math Tutoring in Dutch Primary Education: Evidence from a Disadvantaged Neighborhood in Amsterdam

Last registered on December 20, 2021


Trial Information

General Information

High Dosage Math Tutoring in Dutch Primary Education: Evidence from a Disadvantaged Neighborhood in Amsterdam
Initial registration date
February 03, 2020

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
February 07, 2020, 3:47 PM EST

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Last updated
December 20, 2021, 4:12 AM EST

Last updated is the most recent time when changes to the trial's registration were published.


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Primary Investigator

Erasmus University Rotterdam

Other Primary Investigator(s)

PI Affiliation
University of Amsterdam

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
This study examines the effects of a high-dosage math tutoring program for low achieving 5th grade primary students in a disadvantaged neighborhood in Amsterdam (Amsterdam South-East, The Netherlands). Based on 4th grade test scores, low achieving students were eligible and about half of them were randomly selected to participate in the program. Selected students receive intensive math tutoring in a 2 (students) on 1 (tutor) setting, for 5 days/week, 45 min/day, for an entire school year. Prior to the start of the program, treated and control students scored roughly 1.2 population level standard deviations below the national average.
External Link(s)

Registration Citation

de Ree, Joppe and Bowen Paulle. 2021. "High Dosage Math Tutoring in Dutch Primary Education: Evidence from a Disadvantaged Neighborhood in Amsterdam ." AEA RCT Registry. December 20. https://doi.org/10.1257/rct.4643-1.1
Experimental Details


Randomly selected 5th graders take part in a high dosage math tutoring program. The program was implemented by The Bridge Learning Interventions (www.TBLI.nl). Randomly selected students receive 45 minutes of additional math tutoring classes per day, 5 days a week, for the entire school year. The tutoring took place during regular school hours and replaced some regular instruction. In principle, the tutoring was not meant to replace some of the regular mathematics instruction.

In the beginning of the school year teams of 1 tutor and 2 students were formed. Students and teachers work in these teams for the entire duration of the project. The tutoring classes follow a
mathematics curriculum that is based on the (Dutch) 1F-level, a minimum benchmark level of
achievement that most student should be able to reach by the end of 6th grade. The tutor delivers personalized instruction. Each student's skill level determines the pace at which they work through the curriculum. No steps or subjects are skipped. During the year, tutors build relationships with students and help them develop academic and socioemotional skills (such as confidence). In addition, tutors have weekly phone calls with the parents of their students.

The intention of all parties involved is to repeat the RCT for two more years, for two new cohorts of 5th graders. This however will depend on willingness of (the same or other) schools to participate as well as on funding for implementation.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
5th grade and 6th grade math test scores and secondary school track placement. If technically feasible, we also intend to follow these students into secondary school and monitor track enrollment, regardless of whether we find effects on test scores.
Primary Outcomes (explanation)
For test scores we use tests from the Cito student monitoring system ("leerlingvolgsystemen") as well as TOA tests (math, nonlanguage math) that are collected and administered by The Bridge Learning Interventions. Secondary school track placement is determined in 6th grade, towards the end of primary educuation. Teachers and schools use test results and other information and decide on the secondary school track that best matches the student's level of development. This track recommendation is important and can restrict the options for track enrollment in secondary school.

Secondary Outcomes

Secondary Outcomes (end points)
Reading test scores (Cito and TOA), Strengths and Difficulties Questionnaire
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The intervention takes place in 5 primary schools in the Amsterdam South-East area. Relatively low achieving students (math scores in the bottom 60% nationally) and who are willing to participate (through active consent) were eligible for the tutoring program. A total of 56 (out of 105) students were selected through stratified/block random sampling to take part in the tutoring program.
Experimental Design Details
Not available
Randomization Method
Randomization was done in the office, by computer (Stata)
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
105 students
Sample size: planned number of observations
105 students
Sample size (or number of clusters) by treatment arms
56 in treatment, 49 in control
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Baseline (4th grade) tests can explain about 75% of the variation in the outcome scores (5th grade, and 6th grade tests). The standard deviation of the residual scores (the unexplained variation in the outcome) is about 6.5 score points (i.e. about 0.6 population standard deviations). Based on this (and the sample sizes in treatment and control group) we estimate that the standard error for the estimated treatment effect will be 1.25 score points. The MDE (power: 80%, alpha: 5%) is then 2.8*1.25=3.5 score points, or 0.30 population level standard deviations. Our previous research on a comparable intervention in the Netherlands (but with a bigger sample size) yielded a point estimate of 3.3 score points (or about 0.28 population standard deviations). The present intervention however is more intensive (5 instead of 4 days a week, and in addition to regular math classes (rather than partly replacing regular math classes), for example).

Institutional Review Boards (IRBs)

IRB Name
AISSR (Amsterdam Institute for Social Science Research, University of Amsterdam) Ethical Advisory Board
IRB Approval Date
IRB Approval Number