Longitudinal student tracking systems now serve a multitude of masters. Growing accountability demands from states, accreditors, and the federal government prominently feature such measures as persistence and graduate rates and time-to-degree. At the same time, resource shortfalls are driving institutions and state higher education systems to examine their operations more carefully in order to achieve greater coherence and efficiency; understanding and monitoring student flow is a prominent part of this effort. In light of these developments, student tracking has come of age. This volume describes important changes in the requirements for student tracking data bases and examines the expanding technical possibilities provided by statewide administrative data bases and by the availability of greatly enhanced data-manipulation and statistical tools for constructing and analyzing longitudinal data files. This is the 87th issue of the quarterly journal New Directions for Institutional Research.