Measurement mischief: a critique of Reynolds, Nicolson and Hambly (2003)

Reynolds, Nicolson and Hambly (2003) report an intervention study of the effects of exercise-based training on literacy development, using literacy measures from the Dyslexia Screening Test (DST), the NFER-Nelson Group Reading Test, and the Standard Assessment Tasks (SATs). Investigation of the nature and psychometric characteristics of these measures casts serious doubt on their appropriateness in a study of this nature. Consideration of the findings obtained using these measures does not support the authors' conclusion that reading was improved by the intervention. The study by Reynolds et al. does not demonstrate that exercise-based treatment improves literacy skills and the use of its purported findings as evidence that exercise-based treatment would be beneficial for children with literacy difficulties is scientifically untenable.