Although not a new phenomenon, student swirl and drift continues to grow, and student enrollment patterns are becoming progressively more complex. Many students attend multiple institutions throughout their academic careers, either separately or concurrently, often starting while they are still enrolled in high school. The role of institutional research in helping to define and measure student success, particularly as it relates to retention and persistence, also grows in importance for institutional, state, and national purposes. This chapter will examine strategies for institutional research professionals to address this murky area. Perspectives of both 2-year and 4-year institutions will be explored.