Literacy skills are pivotal for children to become schooled and educated and to engage with written texts in everyday life. Learning to read is a primary skill that children acquire at school. Supervised, supportive guided reading aloud may help children improve their reading skills. However, such a support- ive context is usually difficult to realize at school since teachers do not have enough time to give directed individual feedback. An ASR-based reading tutor could be a solution in such a press- ing situation, as such a tutor can ‘listen' to children reading, provide individual feedback on errors, and store information on reading practice into logfiles. In this study, we investigated the effectiveness of an ASR- based Reading Tutor for Dutch first graders, in which different forms of feedback were implemented. We collected data from 525 first-graders in 44 schools, with 263 pupils who received explicit feedback and 262 pupils who received implicit feed- back. Analyses based on mixed linear regression models indi- cate positive effects of both feedback forms on reading accuracy and a trade-off relationship between accuracy and speed.