At WhatWorked Education, we’re thrilled that our current work aligns perfectly with the EEF’s guidance. In fact, we’ve been busy running a series of pilot micro-RCTs (micro-randomised controlled trials) to test exactly these kinds of TA-led interventions. Backed by the North East Combined Authority (NECA) and with support from Education Durham, we secured funding to pilot these trials across primary schools in County Durham, empowering TAs to lead structured interventions grounded in evidence. These interventions are carefully designed, brief and effective – and they’re being delivered right in the classroom or in small groups, by TAs across Reception to Year 5. We’re essentially turning everyday classroom strategies into robust research, in an effort to build a local evidence base of “what works” in education. 

Examples of TA-led interventions we’re piloting:

• Spelling strategies with “Look, Say, Cover, Write, Check” – using this tried-and-true method to boost spelling, including versions with an extra working memory twist for added benefit (trials in Years 2–5).
• Phonics “keep up and catch up” sessions – same-day support for Reception/Year 1 children who struggle with new phonics sounds or have missed lessons, ensuring no one falls behind.
• Grammar, punctuation, and spelling practice – 15-minute daily bursts using CGP workbooks (Year 3 focus) to reinforce the basics in an engaging, consistent way.
• Number fluency with flashcards – building confidence in Year 1 pupils by practicing number bonds (1–10) through quick, fun flashcard drills and retrieval practice.
• Times tables fluency – targeted multiplication and division practice for Years 3–4, using spaced repetition and interactive techniques to cement those times table facts.
• Reading inference support using visual frames (IEQ model) – helping Years 4–5 pupils tackle 2-3 mark inference questions in reading comprehension by guiding them with the Impression-Evidence-Quote (IEQ) framework.

These trials cover both whole-class approaches and small-group interventions led by TAs. The scope is wide – from early years up to upper primary – because we want to see what works at each stage and setting.

This is part of the wider WhatWorked Teachers North East Evidence Project – an initiative to crowdsource and accumulate evidence with teachers, for teachers in our region. It’s truly about collaboration: TAs and teachers working together to test ideas and share what they find, so that successful strategies can spread across schools.

Research shows that teaching assistants can have a positive impact on pupil achievement – but how TAs are used is critical. General in-class support (e.g. a TA circulating or helping ad-hoc in lessons) often yields minimal or even negative effects on attainment​. Notably, a large UK study found pupils receiving the most routine TA support made less progress than similar pupils who did not – likely because in those cases TA help substituted for time with the qualified teacher​. Simply adding a TA to a classroom does not automatically boost learning. However, when TAs deliver targeted, structured interventions outside the regular class lesson, the story is very different. A systematic review by Farrell et al. (2010) concluded that the academic achievement of primary pupils with learning difficulties (especially in literacy) improved significantly after a period of one-on-one or small-group intervention from a TA, whereas general in-class support had more equivocal effects​. In other words, well-planned interventions led by TAs can substantially boost learning, particularly for students who need extra help.

The evidence highlights a few key features:

• Structured programs: Successful TA interventions usually follow a clear, evidence-based program or curriculum​. This ensures consistency and quality in instruction.
• Short, regular sessions: Instead of ad-hoc assistance, TAs run short tutoring sessions (e.g. 20–40 minutes) a few times per week over a set period​. Consistent scheduling helps reinforce learning.
• Alignment with class teaching: The intervention content is linked to what the student is learning in class​. Teachers and TAs coordinate so that skills practiced in the intervention transfer back to the classroom.
• Supplemental (not replacement) instruction: Crucially, these sessions supplement the teacher’s instruction rather than replace it​. The classroom teacher remains involved in planning and reviewing progress, so pupils still get plenty of time with the teacher.

When these conditions are met, the impact can be impressive. The Education Endowment Foundation (EEF) synthesis of research finds that, on average, well-designed TA interventions add about 3–4 months of additional progress for pupils over a year​. In fact, studies focusing on TAs tutoring individuals or small groups see average gains of +4 to +6 months – a moderate effect that can meaningfully narrow gaps​. For example, a comprehensive meta-analysis by Dietrichson et al. (2017) examined 36 studies of tutoring programs for disadvantaged students and found tutoring by adults (including TAs) had the largest effect size (mean d ≈ 0.36) among 15 types of interventions analysed​. This level of impact, roughly equivalent to four to five months of extra progress, underscores the potential of trained TAs delivering targeted help. Importantly, some research suggests that teaching assistants can be just as effective as teachers in delivering certain interventions. A 2021 meta-analysis of elementary math programs (Pellegrini et al., 2021) reported positive effects for one-to-one and small-group tutoring, and found that outcomes from tutoring delivered by TAs were statistically equivalent to those delivered by qualified teachers​. In other words, a well-supported TA can deliver a tutoring program with similar success as a teacher, especially in structured settings. (Notably, that review also found small-group tutoring slightly outperformed one-to-one in math​, possibly due to peer learning dynamics.) Several specific TA-led interventions have documented success. For instance, programs like Catch Up Literacy and Catch Up Numeracy (one-to-one reading and math support delivered by TAs) have shown significant gains in randomised trials​. In one large-scale trial with 150 schools, TAs delivering Catch Up Numeracy helped improve students’ attitudes toward math, even though overall attainment gains were similar to a control group receiving other support​. Other interventions such as the Nuffield Early Language Intervention (NELI) – a TA-delivered early years language program – have demonstrated strong effects on young children’s vocabulary and language skills in rigorous evaluations (usually adding around +4 months progress in language development) (Fricke et al., 2017, as cited in EEF, 2021).

The consistent theme is that training and structure unlock TAs’ potential. When TAs are prepared with the right tools and used to deliver carefully designed instruction, students benefit. Moreover, teachers report that using TAs this way not only helps learners but also reduces their own workload and stress, since the TA can provide targeted support and feedback that the teacher might struggle to fit in​. Thus, empowering TAs as interventionists can be a win-win for students and teachers alike.