CAT4 Explained for Parents: What the Test Measures and What the Scores Mean

The email from school mentions, almost in passing, that Year 7 will be sitting "CAT4 tests" in the second week of term. Your child comes home and reports a morning of strange puzzles on a computer, shapes, number patterns, odd-one-out words. A few weeks later a parents' evening conversation includes phrases like "her CAT4 suggests she should be achieving more in maths", and you nod along while quietly wondering what on earth a CAT4 is and whether you should be worried.

You are not alone. The CAT4 is one of the most widely used tests in UK schools, hundreds of thousands of children sit it every year, yet most parents are never properly told what it measures, how to read the scores, or how much weight to give them. Some schools share the results readily; others treat them as internal data and only mention them when something looks unusual.

This article gives you CAT4 explained from a parent's point of view: what the test actually assesses, what the numbers and labels mean, how schools use the results, where the test can mislead, and what to do if your child's scores raise questions rather than answer them.

What the CAT4 Actually Is

CAT4 stands for the Cognitive Abilities Test, Fourth Edition, published by GL Assessment. Despite the name, it is not a test of anything your child has been taught. There is no curriculum content, no spellings, no times tables, no history dates. Instead, it measures reasoning ability: how well a child can spot patterns, draw logical connections and solve unfamiliar problems using words, numbers, shapes and spatial thinking.

That distinction matters more than anything else in this article. Attainment tests (like end-of-term exams, SATs or GCSEs) measure what a child has learned. The CAT4 tries to measure how readily a child can learn, what teachers sometimes call potential. Neither is a complete picture on its own, and the most useful information often comes from comparing the two.

The test is taken in school, usually on a computer, in a group setting. It is split into short, timed sections, totalling roughly two and a quarter hours of testing, almost always spread over more than one sitting. Schools commonly run it at the start of Year 7 as a baseline when children arrive at secondary school, though many schools also use it in primary years or at other transition points. Different levels of the test exist for different year groups, so an eight-year-old and a fifteen-year-old sit age-appropriate versions.

One reassurance worth giving your child: nobody passes or fails the CAT4. There is no threshold to clear, no certificate, and no consequence for getting questions wrong. It is an information-gathering exercise for the school.

The Four Batteries: What Each One Measures

The CAT4 reports four separate scores, one for each battery (a battery is simply a group of related subtests, each battery contains two).

• Verbal Reasoning, thinking with words. Tasks include spotting which words belong together and completing verbal analogies ("big is to small as fast is to ___"). This battery leans on vocabulary and the ability to see relationships between ideas expressed in language. It tends to be the strongest predictor of performance in essay-based, language-heavy subjects.
• Quantitative Reasoning, thinking with numbers. Tasks involve number series and number analogies: finding the rule that links one set of numbers and applying it to another. It is not a maths test in the school sense, the arithmetic involved is deliberately simple, but it predicts how readily a child grasps mathematical relationships.
• Non-verbal Reasoning, thinking with shapes and patterns. Children identify which figure completes a matrix or which shape doesn't belong. Because no reading is required, this battery gives the clearest view of reasoning for children whose language skills lag for any reason, including learning in English as an additional language.
• Spatial Ability, thinking with mental images. Tasks involve folding, rotating and combining shapes in the mind's eye. This is the battery parents have usually never heard of, and it can be revealing: some children who struggle to show their thinking in words have genuinely strong spatial minds, a profile common in future engineers, designers and scientists.

Looking at the pattern across the four batteries is more informative than any single number. A child with much stronger verbal than spatial scores learns most easily through language, discussion, reading, written explanation. A child with the reverse profile may understand ideas best through diagrams, models and hands-on work, and may find it frustrating to keep proving understanding in writing. A large gap in either direction is worth knowing about, because classroom teaching defaults heavily to the verbal channel.

How to Read the Scores

CAT4 results come in three main formats, all describing the same underlying performance.

Standard Age Score (SAS). This is the headline number. It compares your child with other children of the same age, not the same year group, which matters for summer-born children, on a scale where the average is 100. The technical scale has a standard deviation of 15, which in plain terms means most children cluster near 100 and scores become rarer the further they sit from it. Roughly two-thirds of children score between about 85 and 115, and GL Assessment describes scores from 89 to 111 as the broad average band. A score of 96 and a score of 104 describe children who are, for practical purposes, similar.

National Percentile Rank. This tells you the percentage of children the same age who scored at or below your child's score. A percentile of 60 means your child scored as well as or better than 60 per cent of the age group. Percentiles are intuitive but bunch up in the middle: a few raw marks can move a mid-range percentile a long way, so don't over-read small differences.

Stanine. A simple 1-to-9 scale (short for "standard nine"), where 5 is average, 1 is the lowest band and 9 the highest. Stanines are deliberately coarse, useful for sorting, hopeless for fine distinctions.

Three rules of thumb when reading a CAT4 report:

• Every score has a margin of error. A child scoring 105 today might score 99 or 111 on another day. Treat scores as regions, not points.
• Differences under about 10 SAS points between batteries are usually noise. Larger, consistent gaps are the ones worth a conversation.
• One sitting is one snapshot. A child who was anxious, unwell, or simply clicked through the non-verbal section quickly because it looked like a game will produce a distorted snapshot.

How Schools Use CAT4 Results

Schools use CAT4 data in several ways, and it helps to know which apply at yours.

Setting and grouping. Many secondary schools use CAT4 scores, alongside primary data, to place children into sets for maths, English and science. This is the use most likely to affect your child's day-to-day experience, and it's a fair question to ask the school directly: "Were CAT4 results used for setting, and what else was considered?"

Target-setting and indicators. CAT4 results generate indicators, statistical estimates of the GCSE grades that children with similar scores have gone on to achieve historically. Some schools convert these into individual targets. It's important to understand what an indicator is: an average drawn from thousands of past students. Real children scatter widely around such averages. An indicator is a starting point for ambition, not a ceiling and not a prophecy, and a school that treats "CAT4 says grade 5" as immovable truth is misusing the tool.

Spotting hidden potential and hidden difficulty. This is the most valuable use. A child whose CAT4 scores sit well above their classroom attainment is underachieving relative to their reasoning ability, and the interesting question is why. Possibilities include a specific learning difficulty such as dyslexia, attention difficulties, low confidence, gaps from earlier schooling, or disengagement. Conversely, a child attaining well despite modest CAT4 scores is working effectively and may be under more strain than their grades suggest.

Identifying support needs. A distinctive profile, strong non-verbal and spatial reasoning alongside much weaker verbal scores, say, can prompt a school to look more closely at reading, language or processing, and to adjust how material is presented.

Where the CAT4 Can Mislead

The CAT4 is a well-constructed test, but it is a group screening instrument, not a clinical assessment, and it has blind spots a parent should know about.

It is timed and computer-based. A bright child who processes information slowly, accurate but unhurried, can run out of time and score well below their true reasoning ability. If your child's report shows scores that surprise you on the low side, and you know them to be a careful, deliberate thinker, slow processing speed is a leading suspect. Notably, the CAT4 itself doesn't measure processing speed or working memory separately, so it cannot tell you whether that's what happened.

It can't see why a score is low. A weak verbal reasoning score could reflect limited vocabulary, a reading difficulty, attention drifting, anxiety, EAL status, or genuinely modest verbal ability. The CAT4 flags the what; it has nothing to say about the cause, and the right response differs completely depending on the cause.

Group conditions hide a lot. In a one-to-one assessment, an examiner notices when a child stops trying, misreads instructions or needs a question repeated. In a hall or computer room with thirty children, nobody notices. Some children, particularly those with attention difficulties, perform far below their ability in exactly these conditions.

It measures reasoning, not everything that matters. Persistence, curiosity, creativity, organisation and emotional regulation all shape school success and are entirely invisible to the CAT4. Reasoning scores predict outcomes only moderately; what a child does with their ability matters enormously.

If the Results Worry You, or Don't Match the Child You Know

Start by asking the school for the actual numbers if you haven't seen them. You are entitled to ask, and most schools will share the SAS scores for each battery. Then look for one of three patterns.

Scores broadly average, attainment broadly fine. Nothing to do. Resist the temptation to compare with other parents' children at the school gate.

A large gap between batteries. Ask the school how teaching and assessment can play to the stronger channel while supporting the weaker one. A strongly spatial child drowning in written tasks, or a strongly verbal child lost in wordless maths notation, often just needs material presented differently.

A gap between reasoning and attainment, in either direction. This is the pattern that most often warrants a deeper look. If CAT4 suggests solid reasoning but reading, spelling, writing or maths attainment lags persistently, something specific may be getting in the way, and group testing cannot tell you what. This is where a structured screening earns its keep: measuring skills the CAT4 doesn't touch, working memory, processing speed, phonological skills, attention and actual academic skills, side by side, so you can see where the bottleneck is before deciding whether a full assessment is justified. A home screening such as GiraffeLens maps these domains in about an hour and shows you whether the profile points towards a full assessment with a psychologist, and where that assessment should focus.

It's worth knowing the cost landscape before you escalate: a full private psychoeducational assessment in the UK typically runs £650-£1,600, and the NHS does not fund dyslexia assessment, so most families pay privately. That makes an intermediate, evidence-gathering step genuinely useful, and it makes the school's own SENCO (Special Educational Needs Coordinator) your first free port of call. Bring the CAT4 scores, your own observations, and ask what the school's data shows across time, not just one sitting.

Questions Worth Asking the School

A short, polite list gets better answers than a long anxious one. These five cover most of what matters:

• "Can I see the SAS scores for each of the four batteries, not just an overall figure?"
• "How do these results compare with how my child is attaining in class, are they achieving in line with their reasoning scores?"
• "Were these results used for setting or targets, and what else informs those decisions?"
• "Is there anything in the profile, gaps between batteries, or between ability and attainment, that you'd want to investigate further?"
• "If there is a concern, what would the school do next, and what can I do at home?"

The CAT4, read properly, is a genuinely useful instrument: one structured, nationally normed view of how your child reasons, taken at a moment in time. Read badly, it becomes a label or a ceiling. Your job as a parent isn't to learn psychometrics, it's to make sure the number serves the child, and never the other way round. If the score matches the child you know, file it and move on. If it doesn't, treat the mismatch as a question worth answering, because behind most mismatches is something fixable, and the earlier it's found, the easier the fix.