The Effect of Doolexia – a Digital Training Method for Students with Dyslexia

Last registered on December 16, 2022

Pre-Trial

Trial Information

General Information

Title
The Effect of Doolexia – a Digital Training Method for Students with Dyslexia
RCT ID
AEARCTR-0010550
Initial registration date
November 30, 2022

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
December 16, 2022, 4:13 PM EST

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

Locations

Region

Primary Investigator

Affiliation
VIVE

Other Primary Investigator(s)

PI Affiliation
VIVE
PI Affiliation
VIVE
PI Affiliation
VIVE

Additional Trial Information

Status
On going
Start date
2022-10-01
End date
2024-01-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
The objective of this trial is to investigate the effect of a new digital training method for students with dyslexia, called Doolexia.

Doolexia is a computer based learning program where the students daily, either in school or at home, train with custom reading and spelling exercises. An adaptive algorithm selects exercises to fit the proficiency of the student. A teacher at the school who is also trained to use Doolexia further supports the intervention with at least two weekly lessons throughout the intervention period. Doolexia is developed by Jan Bay Kønig and Peer Kromann Nielsen and pilot tested in eight schools (Kønig & Nielsen, 2021).

We test the effect of Doolexia on students’ spelling and reading proficiency compared to a control group of students at schools providing the usual dyslexic teaching. We conduct a cluster randomized controlled trial (C-RCT) involving approximately 30 schools and 500 students. We randomize at the school level. Schools assigned the treatment group will receive the intervention in January – June 2023 while the control schools teach as usual. The control schools will receive the intervention in August – December 2023.

The intervention period is about 16 weeks. We will also carry out a fidelity study on the students’ use of the computer program, implementation evaluation among the teachers to examine which factors hinder or improve the implementation of the intervention, and a cost analysis to calculate the intervention’s cost-effectiveness.
External Link(s)

Registration Citation

Citation
Beuchert, Louise et al. 2022. "The Effect of Doolexia – a Digital Training Method for Students with Dyslexia." AEA RCT Registry. December 16. https://doi.org/10.1257/rct.10550-1.0
Sponsors & Partners

Sponsors

Experimental Details

Interventions

Intervention(s)
Doolexia is a computer based learning program where the students daily, either in school or at home, train with custom reading and spelling exercises. An adaptive algorithm selects exercises to fit the proficiency of the student. A teacher at the school, who is also trained to use Doolexia, further supports the intervention with at least two weekly lessons throughout the intervention period.

Doolexia is developed by Jan Bay Kønig and Peer Kromann Nielsen and pilot tested in eight schools (Kønig & Nielsen, 2021).
Intervention Start Date
2023-01-11
Intervention End Date
2023-12-15

Primary Outcomes

Primary Outcomes (end points)
The primary outcomes are students’ spelling test and reading test.
Primary Outcomes (explanation)
The spelling and the reading tests are widely used in Danish primary and lower secondary school to assess and analyze students’ spelling and reading proficiency. They are from the publishing firm Hogrefe Psykologisk Forlag, and the spelling tests (in Danish: Hogrefe ST prøver) are developed by Inger-Lise Heinze and Poul Erik Jensen, and the reading tests (in Danish: Hogrefe læseprøver) are developed by Lene Møller and Holger Juul.

We test the effect on students’ average ‘C-level’ on the spelling test and average ‘K-level’ on the reading test.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We conduct a cluster randomized controlled trial (C-RCT).

The randomization unit is the school. The intervention takes place and is implemented at school level and thus we randomize at school level. All students at the school receives the intervention at the same time. The intervention period is about 16 weeks.

Schools register participating students in October 2022 and complete all pre-tests in October-November 2022. Randomization in November 2022 (conducted by researcher from VIVE). The randomization result is sealed until the day of announcement on November 30, 2022.

Using a waiting-room design, all schools (and thus all students) will at some point during the trial period receive the intervention. Schools assigned the treatment group will receive the intervention in January – June 2023 while the control schools teach as usual. The control schools will receive the intervention in August – December 2023.

Inclusion criteria: In order to participate, the school must sign up at least 7 students passing the inclusion criteria and assign at least one teacher to the intervention (at least two lessons per week throughout the intervention period). For a student to be included, the student must be assessed dyslexic in the Danish national dyslexic test (category ‘red’ or ‘yellow’). Students must be enrolled in grades 4-8 in the academic school year 2022/23.

Exclusion criteria: Students with ADHD or other behavioral or mental diagnosis.
Outcomes: Outcomes are measured at student level.
All participating students complete the spelling and reading test before randomization. These tests will constitute a pre-test. Students complete the same tests after the 16 weeks intervention period and a follow-up test about a half-year later, to evaluate long-term effetcs.

Analysis plan: We use results from spelling and reading tests before and after 16 weeks of using Doolexia (for the treatment group) and 16 weeks of usual dyslexic training (for the control group) to evaluate the average effect of Doolexia.

We test heterogeneous effects with respect to the students’ initial placement on the pre-tests (levels C0-C4 on the spelling test and K1-K5 on the reading test) and school type (public or private).

We test mediating effects with respect to the intervention ‘dosage’ received, meaning how often the students have used the computer program.

We test moderating effects with respect to the variables of stratification (group size and proportion of participants with severe learning difficulties).
Experimental Design Details
Randomization Method
Randomization done in office by a computer using Stata.

The randomization result is sealed until the day of announcement on November 30, 2022.
Randomization Unit
The randomization unit is the school. The intervention takes place and is implemented at school level and thus we randomize at school level. All students at the school receives the intervention at the same time.


Stratification: In order to ensure equal allocation of the participating schools into the treatment and control groups we use stratification before randomization. We stratify on two main characteristics: i) The number of participating students in the trial in each school (above or below 19 students) and ii) the proportion of the participating students who test ‘C0-C2’ on the initial spelling test, meaning that the test indicate they have “severe learning difficulties”. We stratify on these two characteristics to ensure that treatment and control groups are balanced based on how challenged the schools are with respect to dyslexic students.
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
Approx. 34 schools.
Sample size: planned number of observations
Approx. 500 students
Sample size (or number of clusters) by treatment arms
17 schools control group, 17 schools treatment group.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
The Research Ethics Committee, VIVE – The Danish National Center for Social Science Research
IRB Approval Date
2022-08-18
IRB Approval Number
N/A

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials