Education Endowment Foundation:Lexia Reading Core5®

Lexia Reading Core5®

Queen’s University Belfast
Implementation costThe cost estimates in the Toolkits are based on the average cost of delivering the intervention.
Evidence strengthThis rating provides an overall estimate of the robustness of the evidence, to help support professional decision-making in schools.
Impact (months)The impact measure shows the number of additional months of progress made, on average, by children and young people who received the intervention, compared to similar children and young people who did not.
Project info

Independent Evaluator

The York Trials Unit logo
The York Trials Unit
University of York logo
University of York

Testing a computer-based reading programme.

Pupils: 697 Schools: 57 Grant: £280,452
Key Stage: 1 Duration: 2 year(s) 2 month(s) Type of Trial: Efficacy Trial
Completed January 2020

Lexia Reading Core5® (Lexia) aims to improve reading skills and is developed by Lexia Learning Systems LLC. It consists of three elements: personalised online student activities, real-time reporting of student progress, and paper-based resources to guide teacher instruction where needed. Teachers can use it to target struggling readers, as a whole class or whole school intervention, or as a home use supplement to teaching.

In this study, pupils began with the online diagnostic assessment which placed them at the correct starting point in the Lexia programme. They then worked independently on tablets or other devices in small groups away from the classroom setting. Facilitators, who are teachers or teaching assistants (TAs), support pupils in these sessions. Groups of six or seven children took part in each session. Schools were asked to schedule four sessions of 30 minutes per week for those children, for 12 – 24 weeks.

Research has identified remedial and tutorial use of technology as being particularly practical for lower attaining pupils, those with special educational needs or those from disadvantaged backgrounds in providing intensive support to enable them to catch up with their peers. Technology can be particularly useful in personalising learning to match pupils’ individual abilities and needs given the potential for such programmes to adapt and focus on the child’s learning needs.

Lexia Reading Core5® is currently used in over 3,000 schools in the UK. Previous research on Lexia in the US and UK found promising results. This trial is the first opportunity to evaluate the programme using a large-scale RCT within the UK context, using outcomes that measure all-round reading ability. The evaluation also measured the individual skills that compose​‘reading skills’, which allows for comparison with previous studies and to identify any areas of strength or weakness in the programme in terms of enhancing children’s reading development.

Our trial of Lexia involved 697 pupils across 57 schools. The independent evaluation found that children offered Lexia made the equivalent of one additional months’ progress in reading, on average, compared to other children. These results have a high security rating: four out of five on the EEF padlock scale. Children eligible for Free School Meals (FSM) who were offered Lexia made, on average, the equivalent of two additional months’ progress in reading compared to other children eligible for FSM.1

The evaluation also found that the programme had a positive effect on skills that are important for further literacy development.

This was a promising result; the EEF will explore the potential for bringing Lexia to more schools.

1 This version of the report (16 December 2022) presents the hedges’ g effect sizes calculated using unconditional variances as per the statistical analysis plan (SAP). In archived versions of the report, hedges’ g effect sizes had been calculated using conditional variances; this was a deviation from the SAP and has been update.

Both methods of analysis represent a positive effect; however, this update results in an interpretation of fewer months’ progress, from two to one for the primary outcome. The underlying differences are small and do not impact the overarching conclusions about the efficacy of the programme.

  1. Children offered Lexia made the equivalent of one additional months’ progress in reading, on average, compared to other children. This result has a high security rating.
  2. Exploratory analysis suggests that children offered Lexia made the equivalent of two additional months’ progress in word recognition and decoding skills and one additional month of progress in reading fluency and comprehension skills, on average, compared to other children. Children offered Lexia made, on average, no additional progress in Key Stage 1 national test reading raw scores compared to other children.
  3. Children eligible for Free School Meals (FSM) who were offered Lexia made, on average, the equivalent of two additional months’ progress in reading compared to other children eligible for FSM. However, this result has high statistical uncertainty.
  4. Implementation fidelity was high. Most schools incorporated Lexia into their routine so that pupils received the normal provision for struggling readers as well as this intervention. Over three-quarters of survey respondents were satisfied with the access to the online activities, support provided, and the usefulness of the reports.
  5. Most pupils managed to work independently with little scaffolding from teaching assistants. However, teachers and teaching assistants felt that Lexia was unsuitable for a small number of pupils, especially those with Special Educational Needs and Disabilities and those whose reading level was very low.
  6. An alternative analysis shows a slightly higher impact of two months’ progress in reading for all pupils and three months’ progress in reading for FSM pupils (exploratory analysis). This analysis was communicated in the previous version of the evaluation report (see Appendix C) but has been superseded in this evaluation report by the analysis pre-specified before the analysis was conducted. 

Key Conclusions presented in the previous version of this report (published February 2022) can be found in Appendix C of the evaluation report.

ImpactThe size of the difference between pupils in this trial and other pupils
SecurityHow confident are we in this result?
Reading skills
Months' progress
Reading skills (FSM)
Months' progress