CAT4 scores explained

Standard age score (SAS)

The standard age score, or SAS, is the main number. It compares your child's raw score with a large national sample of children of the same age, measured in years and months. The average is 100. Most children score between about 85 and 115.

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 (average) score across all four.

Stanines

Stanine is short for standard nine. It groups scores into nine bands, with 5 in the middle. GL Assessment points out 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 scores.
• Stanines 4 to 6: average, about the middle 54%.
• Stanines 7 to 9: above average, about the highest 23%.

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 as well as or better than 60% of children of the same age. 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 true score is very likely to fall. GL Assessment's own example is a verbal SAS of 100 with a 90% band of about 92 to 108. A difference of a few points between two children, or between two sittings, usually means very little.

The verbal-spatial profile

The report compares verbal and spatial scores. A child whose verbal score is clearly higher has a verbal bias; one whose spatial score is clearly higher has a spatial bias; similar scores mean no bias. Reports describe a bias as mild or extreme depending on the size of the gap.

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 SAS 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. Schools usually take this into account, and the non-verbal and spatial batteries do not depend on reading.

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.