The effectiveness of online tutoring in secondary school: Evidence from a randomized controlled trial

Last registered on March 24, 2022


Trial Information

General Information

The effectiveness of online tutoring in secondary school: Evidence from a randomized controlled trial
Initial registration date
March 29, 2021

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
March 30, 2021, 6:24 AM EDT

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

Last updated
March 24, 2022, 6:34 AM EDT

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



Primary Investigator


Other Primary Investigator(s)

PI Affiliation
PI Affiliation
World Bank

Additional Trial Information

Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Evidence is mounting that there is a substantial socio-economic gap in learning losses experienced by students as a result of widespread school closures in response to the COVID-19 pandemic. This research evaluates the effectiveness of an online tutoring program aimed at students from highly disadvantaged schools in Spain. We will randomly assign students to tutors. Students will be taught in groups of two for a duration of eight weeks. We will evaluate the effect of the program both on cognitive as well as socio-emotional outcomes.
External Link(s)

Registration Citation

Gortazar, Lucas, Claudia Hupkau and Antonio Roldan. 2022. "The effectiveness of online tutoring in secondary school: Evidence from a randomized controlled trial." AEA RCT Registry. March 24.
Sponsors & Partners

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Experimental Details


The intervention consists of tutoring in maths with a focus on emotional wellbeing, delivered online over the course of 8 weeks (3 hours per week) in groups of 2 students.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
We will study the impact of the intervention on cognitive as well as non-cognitive outcomes:
Cognitive outcomes are measured by scores using a standardized test that will be administered online during school hours. In additional, we will be looking at end-of-year grades and whether the subject was passed, and whether the student had to repeat a school year. Non-cognitive outcomes will be measured via a self-completion survey to students covering socio-emotional skills, locus of control, aspirations, and wellbeing.

Primary Outcomes (explanation)
Cognitive skills: Test score on standardized exam: We have developed two exams (one for each year group participating). These are exams consisting of 6 to 7 questions with multiple choice answers. We will compute the score on the exam and standardize it within each year group. Other outcomes will be collected from parent surveys and include the end of yera grade in maths, whether the subject was passed (stduent received at least a score of 5 out of 10) and whether the student had to repeat the school year (grade retention).

Socio-emotional skills: Subjective wellbeing, aspirations, locus of control and grit: We will construct indices of the aforementioned aspects using answers to several questions in each domain in the endline survey.

Secondary Outcomes

Secondary Outcomes (end points)
Because students are assigned randmly to groups of 2 for their tutoring sessions (within the same classrooms or year group within school) we will further test whether (1) whether the ability match matters (measured through baseline maths test results) (2) whether the gender compisition of the group matters for effectiveness.

Due to the fact that we randomly assign tutors to students, we will study heterogeneous effects of the intervention with respect to tutor-student gender match.

Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Due to limited financial resources to pay additional tutors, among all students who register interest for the program, only some students will be randmly assigned to a mentor.
Experimental Design Details
Randomization Method
Randomization done in office by a computer.
Randomization Unit
The unit of randomization are individuals. Randomization will be blocked at the classroom or year group level (depending on the number of students registering per classroom in a given school).
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
We have registered interest to participate by about 380 students from 18 schools. These 380 students will be randomly assigned to one of three treatment arms: 1) tutoring and 2) control group (no tutoring).

Sample size: planned number of observations
We plan to have 380 pupils in our study.
Sample size (or number of clusters) by treatment arms
The targeted sample size is 200 students for the treatment group, and 180 students in the control group.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
MDES for main outcomes: 29% of a standard deviation (standardized test score in maths)

Institutional Review Boards (IRBs)

IRB Name
Research Ethics Committee (CER-URL)
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Intervention Completion Date
June 04, 2021, 12:00 +00:00
Data Collection Complete
Data Collection Completion Date
August 31, 2021, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
356 students from 18 schools
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
356 students from 18 schools
Final Sample Size (or Number of Clusters) by Treatment Arms
186 students in treatment group, 170 in control group
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials