This paper summarizes a study that was conducted on data from children who received a one-on-one intervention called Reading Recovery[R] during the first half of their first-grade year in school. The purpose was to investigate the relationship between accelerated progress children made during and after receiving a Reading Recovery intervention, and to determine if a prediction could be made of children's progress following a series of Reading Recovery lessons. The measure used to assess progress in literacy development was Text Reading Level (TRL), a subtask of "An Observation Survey of Early Literacy Achievement" (Clay, 2006). The findings show a moderate relationship between students' progress following a series of Reading Recovery lessons to the end of first grade, suggesting the sustained effect of the intervention. Additionally, intervention length was noted to be a significant predictor of year-end TRL. Students who had progressed through their series of lessons at a quick rate and had the same TRL at mid-year were shown to have higher TRL scores at year-end. Plotting odds of success (defined as reaching a year-end TRL greater than 18 or 20) for length of intervention and mid-year TRL revealed that students who accelerated through the intervention quickly did not need to reach as high a TRL by the end of the intervention compared to students who did not progress as fast. Although mid-year TRL was known to be important in predicting success after an intervention, no empirical determination of which level was predictive existed prior to this study. (Contains 4 tables and 1 figure.)