The Matrix Reasoning subtest presents children with incomplete matrices of images and asks them to select an image to complete each matrix from a choice of options. For children up to the age of 8, there are 24 possible matrices to complete. For children aged 9 years and older, there are 30 possible matrices to complete. The test is discontinued when the child selects three consecutive incorrect responses. Trials correct are converted to T-scores (M = 50, SD = 10). Closest-age matching was used to derive age-referenced scores for children outside the age-normed reference frame (e.g. under 6 years old).