National rollout in 10,000 schools in England shows language intervention can work at scale

What is it about?

Many children start school with weak oral language skills, which can put them at risk of long-term learning difficulties. While the Nuffield Early Language Intervention (NELI) has been shown to work well in controlled trials, it was not clear whether it would be as effective when delivered at a much larger scale in real schools. As part of the UK government’s COVID-19 recovery response, NELI was rolled out to over 10,000 schools in England. To make this possible, the programme was adapted: teachers were trained online, ongoing practitioner support was provided, and an automated assessment helped identify children who most needed help. The impact of NELI was then measured using a regression discontinuity design, which compares children who just qualified for the programme with those who narrowly missed eligibility.

Why is it important?

Analysis of nearly 20,000 children showed that those who received NELI made significantly greater improvements in their language skills than those who did not. The effect size (Hedges’ g = 0.40) shows that children receiving NELI made meaningful progress. This study provides rare large-scale evidence that NELI not only works in tightly controlled research trials but also improves children’s language skills in real classrooms across thousands of schools. This supports its use as a practical, evidence-based programme that can help children with early language weaknesses.