A 7-month study of 178 students in grades 1-4 at two Blue Ribbon schools compared two daily 20-minute treatments. Eighty-eight students used the 2000-2001 version of Project LISTEN's Reading Tutor (www.cs.cmu.edu/~listen) in 10-computer labs, averaging 19 hours over the course of the year. The Reading Tutor served as a computerized implementation of the National Reading Panel's recommended guided oral reading instruction (NRP, 2000). The Reading Tutor listened to students read aloud, giving spoken and graphical help when it noticed them click for help, make a mistake, or get stuck. Students using the Reading Tutor averaged significantly higher gains across measures of reading ability, especially those involving word level skills (word identification, blending words, and spelling) than their matched classmates who spent that time doing Sustained Silent Reading (SSR) in their classrooms. Additionally, these students trended toward higher gains in fluency and reading comprehension. Overall, use of the Reading Tutor resulted in the types of improvement that would be expected from guided oral reading, but with the benefit of scalability, a problem for human-guided oral reading practice.