This paper describes an evaluation of an internet-based reading programme called Accelerated Reader (AR), which is widely used in UK schools and worldwide. AR is a whole-group reading management and monitoring programme that aims to stimulate the habit of independent reading among primary and secondary age pupils. The evaluation involved 349 pupils in Year 7 who had not achieved secure National Curriculum Level 4 in their Key Stage 2 results for English, randomised to two groups. The intervention group of 166 pupils was exposed to AR for 20 weeks, after which they recorded higher literacy scores in the New Group Reading Test (NGRT) post-test than the control group of 183 pupils ("effect" size of +0.24). The schools led the organisation and implementation of the intervention, and also conducted most elements of the evaluation, with advice from an expert external evaluation team. The process evaluation suggests that these schools were very capable of conducting evaluations of their own practice, given appropriate guidance.