This article explores the use of longitudinal regression as a tool for identifying scoring inaccuracies. Student progression patterns, as evaluated through longitudinal regressions, typically are more stable from year to year than are scale score distributions and statistics, which require representative samples to conduct credibility checks. Historical data from a large-scale K-12 testing program were used to evaluate the usefulness of several proposed longitudinal procedures. Results showed that the use of longitudinal regression in quality control was effective in detecting scoring errors, especially when the scoring errors were non-negligible.