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How can CAT4 and NGRT be used together to support student transition and identify underachievement?
When CAT4 verbal reasoning scores are placed alongside NGRT reading results, educators can compare what a student is cognitively capable of against what they are actually achieving in reading. Where those two numbers don't align, it is a direct signal to investigate further — not to wait. The discrepancy categories built into this combined approach are statistically grounded, covering the full distribution of score differences across large datasets, so the flag isn't a guess: it's a measured divergence from what is expected.
A statistical framework that turns two scores into a meaningful gap
The CAT4 measures cognitive ability — including verbal reasoning — while the NGRT (New Group Reading Test) measures reading attainment. Used in isolation, each gives a useful snapshot. Used together, as Georgina Cook and Emma Dibden explain in Education: Joining the Dots, they reveal something far more actionable: whether a student's reading is where their cognitive potential would predict it to be.
The discrepancy categories are built on distributions from large datasets and are structured as follows:
Expected range — covers the middle 50% of score differences. A student falling here is reading broadly in line with their cognitive potential.
Higher / Lower than expected — the next 15% on each side. The student's reading attainment is noticeably above or below what CAT4 verbal reasoning would predict.
Much higher / Much lower than expected — the top or bottom 10%. This is the sharpest signal: reading attainment is significantly misaligned with cognitive potential, in either direction, and warrants close investigation.
A student scoring "much lower than expected" is not simply a weak reader — they are a capable learner whose reading hasn't kept pace with their ability. That distinction matters enormously for how a school responds, and it is exactly the kind of nuance that a combined CAT4 and NGRT analysis surfaces, as discussed in depth in this episode.
Diagnosing on entry — not after the damage is done
The practical power of this approach depends heavily on timing. At Bishop Wilkinson Catholic Education Trust, the NGRT is administered to Year 6 pupils over a three-week window in May and June. All diagnostic data — including discrepancy categories — is available by mid-June, well before pupils arrive in September. That window is not incidental: it gives secondary teachers real intelligence about each incoming student before the first day of term.
Talia Caralambos, speaking from her experience leading literacy across Laidlaw Schools Trust — where one school in the West End of Newcastle has over 60 languages spoken by its pupils — makes the urgency explicit. The question isn't whether to act, it's when. And the answer, informed by CAT4 and NGRT used together, is: on entry. This approach is one of the central arguments of the episode on student transition.
"Don't wait until a child is failing to act. You need to diagnose on entry, involve staff from the start, and if you're fortunate enough to have digital tools that you can access, align that to your transition work, because it can be transformational."
Talia Caralambos — Director of English, School Improvement Team, Laidlaw Schools Trust.
Caralambos trained and taught English and Media at Ritchie Diver Secondary School in London before relocating to the North East. She comes from a bilingual household and first taught English in India at age 17 — an experience she credits as the origin of her commitment to equity through literacy. At Laidlaw Schools Trust, she leads curriculum development and literacy improvement across 11 schools, many of which serve communities with high mobility, economic disadvantage, and exceptional linguistic diversity.
The logic Caralambos articulates applies directly to the CAT4/NGRT combination: digital, statistically robust tools are only transformational if they are deployed early enough and shared widely enough across staff. Data that sits in a spreadsheet until October has already missed the window that matters most — a point developed further in Education: Joining the Dots.
See also
What advice do transition programme leaders give to educators building their own primary-to-secondary literacy transition plan?
Graeme Finlay advises careful liaison with GL Assessment over several months to design a reading strategy before selecting tools, and stresses that staff involvement from the outset is essential — assessment should never be a data exercise for leadership alone.
What is the 'six-week dip' in the context of student transition, and how do these trusts address it?
The 'six-week dip' refers to the period after summer where students readjust to school routines and may lose academic momentum, particularly in reading. Both trusts address it by ensuring diagnostic data reaches secondary schools before September, so targeted support can begin from day one.
Why does Bishop Wilkinson Catholic Education Trust administer NGRT in Year 6 rather than waiting until September of Year 7?
Graeme Finlay explains that previously some secondary schools were administering the NGRT in September, which created a lag between identifying children who needed support and actually providing it. Administering in Year 6 — with all data available by mid-June — closes that gap entirely.
Key takeaways
- Placing CAT4 verbal reasoning scores alongside NGRT reading results reveals whether a student's attainment matches their cognitive potential — not just how they perform in absolute terms.
- The discrepancy categories are statistically grounded: the expected range covers the middle 50% of score differences, with the outer 15% and 10% on each side flagging progressively greater misalignment.
- Timing is decisive — having combined CAT4 and NGRT data available before September means secondary teachers can act from the first day of term, not weeks into it.
- A "much lower than expected" flag identifies capable learners whose reading has fallen behind their potential — a qualitatively different intervention need than general low attainment.
This question was answered in the Education: Joining the Dots podcast. Hear the full conversation on Listenly.
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