School psychologists regularly use decision rules to interpret student response to intervention in reading. Recent research suggests that the accuracy of those decision rules depends on the duration of progress monitoring, the number of observations available, and the amount of measurement error present. In this study, we extended existing research to evaluate the influence of a student's initial level of performance, goal line type, and decision rule type on the accuracy of interpretations of progress monitoring data. Normative goal lines performed best for students scoring far below benchmark at the beginning of the year, while goal lines based upon a spring benchmark score were appropriate for students performing just below expectations at the beginning of the year. The data point rule performed poorly across all progress monitoring conditions, while comparing the median of the 3 most recent observations to a goal line performed similarly to the trend line rule.