How do we measure the impact of TA support?

Start with a baseline against agreed outcomes

Measure TA impact by baselining each pupil against SMART outcomes, then reviewing progress to an agreed date within the assess-plan-do-review cycle, using entry and exit assessment for structured interventions. The method is the same whether the pupil is on SEN Support or has an EHC plan.

The first job is the baseline. Before the support starts, record where the pupil is now against the specific outcome you have agreed with them and their parents, not against the class average and not against an end-of-year target. If the outcome is “reads 40 high-frequency words on sight by February”, the baseline is the number they read today. A vague outcome can never be measured, so write the outcome to be measurable before you deploy the TA.

This is where the assess-plan-do-review cycle does the work for you. At the plan stage, the SEND Code of Practice 2015 asks you to agree the support, the expected impact on progress, and a clear date for review (paragraphs 6.44–6.56). Good practice is to write that expected impact so it says how progress will be measured, by whom and by when. That gives you a measurement framework already built into the statutory cycle the school must run.

Review progress to the agreed date

At review, the duty is explicit: the effectiveness and impact of the support must be evaluated against the agreed date, with the views of the pupil and parents, and fed back into your analysis of need (SEND Code 2015, paragraphs 6.53–6.55). A review that only asks “did the TA do the sessions?” misses the point. You are measuring movement towards the outcome, not hours delivered.

For a structured intervention, the evidence is concrete:

1. Entry assessment on the skill the intervention targets, taken in the first session.
2. Exit assessment on the same measure at the end of the block. Structured interventions are usually brief (20–50 minutes), regular (3–5 times a week) and sustained over 8–20 weeks (EEF, Deployment of Teaching Assistants, March 2025, which superseded the 2015 Making Best Use of Teaching Assistants report).
3. The gap closed between the two, set beside the agreed outcome, is your impact evidence for the review.

Keep the class or subject teacher in the room for this. The teacher remains responsible for the pupil's progress even where a TA delivers the support, so the review judgement is theirs to make, not the TA's alone.

Separate intervention impact from in-class deployment

The common error, and the one a governor or inspector will find, is measuring all TA support as one thing. It is two things, and they are measured differently.

• Targeted structured interventions are measured by entry and exit assessment as above. The EEF Teaching Assistant Interventions Toolkit strand (2024 update) reports that well-delivered structured TA interventions add +4 months' progress on average, at very low cost, expressed as additional months of progress against a comparison group.
• General in-class deployment is measured by whether it increases the pupil's access to good teaching, not by attainment alone. The EEF warns that velcro-style one-to-one support can reduce a pupil's contact with the teacher and harm outcomes, so here you track teacher contact time and the pupil's growing independence, not just test scores. How you assign TAs in the first place, to pupils or to interventions, shapes which of these two measures you will mostly be reading.

Conflating the two hides your real impact: the structured work that is moving outcomes gets averaged out against deployment that may be doing nothing. Report them apart.

One eye on the horizon: the 2026 Schools White Paper Every child achieving and thriving proposes a statutory Individual Support Plan for every child with identified SEND, recording the support given and how its impact is reviewed (House of Commons Library, 2026). It is a consultation proposal, not yet law, and it does not change the current assess-plan-do-review duty, but it points the same way, so the records you build now will carry over.

This page is general information, not clinical or legal advice.