In 1995, doctoral degrees were granted to over 26,000 individuals in the sciences and humanities; however, many other individuals began graduate work with the same aspirations. There are no national estimates to indicate how many students make the decision each year to cease graduate work, but studies at a few selected academic institutions suggest that as many as half the students entering certain programs do not complete their degrees. This book discusses current approaches to the measurement of graduate attrition and identifying factors thought to contribute to it. A listing of databases for studies of graduate education in the United States, the basic design of a longitudinal tracking system for doctoral students, and an annotated bibliography are included. (DDR)