Around 6% of U.K. children are underachieving at school relative to their potential (URP). We explored whether difficulties with phonological decoding, short-term memory (STM), and complex grammar may be responsible. We compared school-based reading test data or formal SATs, and verbal reasoning in 2462 children (150 URP and 2312 non-URP children)…

Background: A fundamental aim of standardized educational assessment is to achieve reliable discrimination between students differing in the knowledge, skills and abilities assessed. However, questions of the purity with which these tests index students' genuine abilities have arisen. Specifically, literacy and numeracy assessments may also engage…