Assessment and language intervention evidence
Learn about the academic research trials and independent evaluations carried out on our assessment apps and interventions to evaluate their effectiveness in mainstream schools. Below are the key findings from these studies providing clear insights into their impact on children’s language and behaviour in schools.
A summary of this research is available on our research overview page.
The Nuffield Early Language Intervention (NELI) programme is associated with lasting improvements in children’s language and reading skills (2025)
Charles Hulme, Gillian West, Mariela Rios Diaz, Sarah Hearne, Caroline Korell, Mihaela Duta, Margaret J. Snowling
The Journal of Child Psychology and Psychiatry
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Oral language skills are a critical foundation for education and psychosocial development. Learning to read, in particular, depends heavily on oral language skills. The NELI Intervention has been shown to improve the language skills of 4-5 year old children entering school with language weaknesses in four robust trials. A large-scale effectiveness trial of NELI implemented under real-world conditions produced educationally meaningful improvements in children’s language and reading abilities. In this paper we report follow-up testing of children from this study conducted approximately 2 years after the completion of the initial intervention.
- When tested at the two year follow up, children who had received NELI had better oral language skills that the control group.
- Children who received NELI also had better reading comprehension and single word reading than the control group.
- Although fade-out effects are common in educational research, NELI produces lasting improvements in language and reading.
- The effect sizes seen are educationally important, especially in the context of NELI being low cost and scalable.
LanguageScreen: The Development, Validation, and Standardization of an Automated Language Assessment App (2024)
Charles Hulme, Joshua McGrane, Mihaela Duta, Gillian West, Denise Cripps, Abhishek Dasgupta, Sarah Hearne, Rachel Gardner, and Margaret Snowling.
Language, Speech and Hearing Services in Schools
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Oral language skills provide a critical foundation for formal education and especially for the development of children’s literacy (reading and spelling) skills. It is therefore important for teachers to be able to assess children’s language skills, especially if they are concerned about their learning. This study reports the development and standardisation of a mobile app—LanguageScreen—that can be used by education professionals to assess children’s language ability.
- Approximately 350,000 children were included in the standardisation sample, spanning ages 3.5-9 years old.
- The LanguageScreen total score gives the best estimate of a child’s language level with good-to-excellent reliability for the total score.
- LanguageScreen correlates well with much longer, well-standardised tests of language ability and is sensitive to improvements in language skills brought about by intervention.
Early language screening [LanguageScreen] and intervention [NELI] can be delivered successfully at scale: evidence from a cluster randomized controlled trial (2021)
Gillian West, Margaret J. Snowling, Arne Lervåg, Elizabeth Buchanan-Worster, Mihaela Duta, Alexandra Hall, Henrietta McLachlan, and Charles Hulme
The Journal of Child Psychology and Psychiatry
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This study provides strong evidence that language intervention delivered in mainstream schools can significantly improve children’s language skills.
- A 10 to 15-minute LanguageScreen test administered by teachers and/or teaching assistants could be used reliably to identify children in need of support with language development.
- Children receiving the language intervention demonstrated significantly larger gains in their language skills compared to the control group.
- The positive effects of intervention were consistent across genders and among English as an Additional Language (EAL) children.
This paper was one of the top ten most downloaded research papers from The Journal of Child Psychology and Psychiatry in 2021
Early language intervention [NELI] improves behavioral adjustment in school: evidence from a randomized trial (2022)
Gillian West, Arne Lervåg, Margaret J. Snowling, Elizabeth Buchanan-Worster, Mihaela Duta, Charles Hulme
Journal of School Psychology
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This study demonstrates that a school-delivered language intervention programme has positive effects on teachers’ ratings of children’s behaviour in school.
- Based on a large randomized controlled trial the research showed greater improvements in the behaviour of children who participated in the language intervention than those who didn’t.
- The study suggests that the NELI programme requirements such as sitting still, listening, and participating in small group and individual sessions, along with rewarding children for participating in the programme, contribute to these improvements.
NELI scale-up impact evaluation (2023)
Education Endowment Fund
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This impact evaluation, conducted by NFER, evaluated the impact of NELI delivered at national scale on children’s oral language skills.
- Children who received the NELI programme made on average the equivalent of 4 months’ additional progress in language skills compared to those who did not receive the intervention.
- Additionally, children with English as an Additional Language (EAL) made the same progress as their peers.
- Children eligible for free school meals made the equivalent of 7 months’ additional progress as a result of participating in the NELI Programme.
Delivering Language Intervention at Scale: Promises and Pitfalls (2022)
Margaret J. Snowling, Gillian West, Silke Fricke, Claudine Bowyer-Crane, Julia Dilnot, Denise Cripps, Marysia Nash, Charles Hulme
Journal of Research in Reading
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There is now substantial evidence that language interventions delivered to small groups can be effective for improving language skills and hence strengthening the foundation for formal schooling. However, there are remaining challenges when delivering such interventions in naturalistic environments at scale. This paper reflects on three randomised trials designed to evaluate the impact of an early years language programme [NELI], prior to the implementation of a large effectiveness trial, delivered in partnership with speech and language professionals.
- The paper provides an overview of three published trials and reflects on the issue of implementation at scale.
- The paper presents a schools’ perspective on the qualitative findings from educational practitioners who delivered the intervention, based on questionnaires and interviews.
- The paper demonstrates how theoretically motivated interventions can be adapted for delivery at scale.
This paper is one of the top ten most cited publications in the Journal of Research in Reading.
Training Teaching Assistants to support early language development (2020)
Education Endowment Fund – Second Efficacy Evaluation
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This independent report evaluated the NELI programme under everyday conditions in schools.
- Children who received the language intervention made the equivalent of 3-5 months additional progress in language and reading skills compared to those who did not receive the intervention.
- Children’s word reading skills also improved.
- Additionally, children with English as an Additional Language (EAL) made the same progress as their peers.
- Surveys and interviews revealed that schools found the training and ongoing support provided for NELI to be clear, useful, and sufficiently detailed for efficient delivery of the intervention.
- A follow up study of children from this study showed that the gains in their language and word reading were still present two years after the intervention had finished. Such durable effects of an intervention are rare.
National scale-up of NELI to support COVID-19 education recovery (2021)
Education Endowment Fund (EEF) – Scale Up Trial
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Following successful effectiveness trials, the Department for Education (DfE) provided funds to scale up the NELI programme to over 10,000 schools over two years. Independent evaluations overseen by the EEF explored the success of this large-scale implementation.
- Delivering training online, and at scale, worked well with most school staff feeling prepared to deliver the intervention after training.
- Despite challenges posed by national lockdowns and ongoing disruptions from Covid-19, teachers and teaching assistants involved in the programme reported a positive effect on pupils’ confidence and language abilities, with 70% indicating they would deliver the intervention the following year.
Improving spoken language skills in young children around the time that they start school (2014)
Education Endowment Fund – Initial Efficacy Evaluation
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This independent study evaluated the NELI Programme under regular conditions in schools.
- NELI had a positive effect on the language skills of children in the trial.
- Staff also reported that the programme had a positive effect on children’s confidence, reporting that the small group format, activities covered and the focus on narrative and vocabulary work contributed to this effect.