Young pupils’ language skills found to improve due to a national scale programme

By NFER Senior Research Manager, Aarti Sahasranaman.

Tuesday 19 September 2023

There is strong evidence that the Nuffield Early Language Intervention (NELI), a small group intervention consisting of group and individual sessions and delivered by teaching assistants (TAs), can improve the language skills of pupils.

EEF-funded efficacy and effectiveness trials have previously demonstrated that the 20-week version of NELI delivered to Reception pupils with weak oral language skills had positive impacts on the language skills of pupils receiving the intervention (Sibieta et al., 2016, Dimova et al., 2021).

Recognising this positive impact of NELI, the Department for Education (DfE), as part of the Government’s education recovery efforts during the COVID-19 pandemic, committed £9 million to make NELI available to state-funded primary schools in England with Reception pupils (DfE and Ford, 2021).

In the first wave in the 2020/21 academic year, around 6,500 primary schools registered to receive NELI. Given the demand for NELI in wave 1 and the continued impact of lockdowns, the DfE committed a further £8 million to expand access to NELI in the 2021/22 academic year.

Approximately 4,000 additional schools registered to receive NELI in wave 2 of this national roll-out. Although an impact evaluation of wave 1 was planned, it was ultimately not commissioned because of school closures mandated by the COVID-19 pandemic. In March 2022, NFER was commissioned to conduct an independent impact evaluation of the wave 2 national roll-out of NELI.

Our impact evaluation used a quasi-experimental Fuzzy Regression Discontinuity Design (RDD) to estimate the effect of NELI on pupils’ language skills. Typically, RDD is used when individuals are assigned to the intervention group based on whether they are above or below a certain threshold. For example, in this evaluation, each pupil’s LanguageScreen score (the measure of a pupil’s language skills) at baseline was used to determine whether or not the pupil should receive NELI.

The intervention developers recommended that three to six pupils in each class with the lowest LanguageScreen scores should receive NELI. This was mostly followed, although in practice teachers also used other factors in addition to the LanguageScreen score, such as behavioural factors, to decide which pupils should receive the intervention.

RDD estimated the effect of NELI by comparing the LanguageScreen scores of pupils just below the threshold score (received NELI) and those above the threshold (did not receive NELI) as the expectation is that pupils close to the threshold are very similar in all other ways than receiving NELI.

We found that pupils who received NELI made an additional four months’ progress, on average, in language skills compared to pupils who did not receive NELI.

NELI also had positive impacts on the language skills of pupils eligible for Free School Meals (FSM). FSM-eligible pupils who received NELI made, on average, seven months’ progress in language skills compared to FSM-eligible pupils who did not receive the intervention.

While our analysis also found that NELI had a positive impact on the language skills of pupils with English as an Additional Language (EAL), our sample for this subgroup analysis was small and insufficient to confidently interpret our finding. Our exploratory analysis highlighted that the effect of receiving NELI was greater for pupils whose TAs delivered more group sessions than those whose TAs delivered fewer group sessions. Therefore, even when a lower than intended dosage of NELI was delivered, we found, on average, a positive impact on pupils’ language outcomes.

The fully validated and highly reliable LanguageScreen assessment, used as the primary outcome measure for this trial, was chosen as it assesses aspects of language development that NELI is intended to target. The measure is completely appropriate to capture these aspects of a Reception child’s development and a necessary choice for this age group.

When thinking about the success of this programme in the wider context of large-scale evaluation, it is noticeable that the measure is more proximal than some end-of-year tests or high-stakes assessments that might form primary outcome measures in other trials.

It is possible that some of NELI’s relative success can be explained by this proximity (Sims et al, 2023). However, this in no way detracts from the programme’s huge potential to help Reception children improve their language skills. NELI’s positive impact on the oral language skills of FSM-eligible pupils shows promise to close the ‘language gap’.


DfE and Ford, V. (2021) ‘Every School with Reception Class Offered Early Language Training’, GOV.UK.

Dimova, S., Illie, S., Rosa Brown, E., Broeks, M., Culora, A. and Sutherland, A. (2020) ‘The Nuffield Early Language Intervention. Evaluation Report’ [PDF].

Sibieta, L., Kotecha, M. and Skipp, A. (2016) ‘Nuffield Early Language Intervention: Evaluation Report and Executive Summary’.

Sims, S., Anders, J., Inglis, M., Lortie-Forgues, H., Styles, B., & Weidmann, B. (2022). Experimental education research: rethinking why, how and when to use random assignment (CEPEO Working Paper No. 23-07). Centre for Education Policy and Equalising Opportunities, UCL.