CAT score, relationship to eleven plus performance, boys

[Tolstoy]

Somewhere there is a record of the average CAT score for the children attending each of the schools. Crypt I think was 115, Tommies 120 and Pates 125. This would support the fact that these CAT scores are a fairly accurate indicator of how well you will do in the test.

[Etienne]

An average doesn't help in terms of how reliable the results may be in an individual case.

NFER (as it then was) used to provide the following warning on the printout of each child's CAT scores:

Important notes: A pupil's SAS scores are only an estimate of true ability as performance on any one occasion can be affected by a number of factors such as mood, illness, external distractions etc. So, on another day, the same pupil could get a different score. Statistical methods can be used to estimate the range of scores within which you can be 90% sure that the pupil's true score lies. These confidence bands are shown on the graph.

As an example:
VR 116, 90% chance true score in the range 109-121
Q 113, 90% chance true score in the range 105-118
NVR 102, 90% chance true score in the range 96-107