CAT4 scores explained

Standard age score (SAS)

The standard age score, or SAS, is the main number. It compares your child's raw score, adjusted for age, with a nationally representative sample of children of the same age. The average is 100.

Because the score is adjusted for age, a child who is young for the year group is not penalised for being younger than classmates.

There is a score for each of the four batteries, and a mean score, which is the average of the four.

Stanines

Stanine is short for standard nine. It groups scores into nine bands, with 5 in the middle. GL Assessment notes that stanines are easy to read and avoid the impression that the scores are IQ scores.

• Stanines 1 to 3: below average, about the lowest 23% of children. Standard age scores of 88 and below.
• Stanines 4 to 6: average, about the middle 54%. Standard age scores of about 89 to 111.
• Stanines 7 to 9: above average, about the highest 23%. Standard age scores of 112 and above.

National percentile rank (NPR)

The national percentile rank, or NPR, shows the percentage of children in the national sample who scored the same or lower. An NPR of 60 means your child scored the same as or better than 60% of children of the same age in the national sample. It is not a percentage of questions answered correctly.

Confidence bands

No test is perfectly precise, so reports show a confidence band: the range in which a child's score would be expected to fall on 9 out of 10 test occasions. For the CAT4 the band is typically about five points either side of the score, and it varies by level, battery and the score itself.

GL Assessment's own example: a child who scores 95 and is tested again months later and scores 98 has not really changed, because the second score is well within the band. A difference of a few points between two children, or two sittings, usually means very little.

The verbal-spatial profile

The verbal and spatial scores are compared to give a profile. GL Assessment's reports use seven descriptions: extreme, moderate or mild verbal bias; no bias; or mild, moderate or extreme spatial bias. No bias is the most common, because verbal and spatial ability tend to go together.

A bias is not good or bad. It suggests how a child may learn best: a spatial learner often benefits from diagrams and models, a verbal learner from discussion and reading. GL Assessment treats a gap of 10 or more standard age score points between batteries as significant.

How admissions teams use the scores

Some schools look for a minimum mean SAS, others read the profile alongside reports and an interview, and some use the CAT4 mainly to plan support once a child has a place. Thresholds are set by each school and can change, so ask the admissions team directly how the results are used.

If your child is still learning English, verbal scores may understate their reasoning. The non-verbal and spatial batteries do not depend on reading or English, which GL Assessment notes makes them useful for students with English as an additional language. Ask the school how it takes this into account.

Questions to ask the school

• Which level did my child take, and was it the usual one for their age?
• How do you use the CAT4 alongside other information?
• Is there a score you look for, or is it read as a profile?
• Will my child's English be taken into account for the verbal battery?

What Merlin Practice shows instead

Merlin Practice does not produce standard age scores, stanines or percentiles. Those come only from the real test, standardised on a national sample. Our parent report shows which question types feel familiar and which need more practice, in plain English.