Using a data base compiled by the Graduate School of Northwestern University, a longitudinal study of the graduate school careers of 2,211 students in 14 programs was conducted. Among the most prominent findings was the increase in the enrollment of foreign students. The patterns of attainment of graduate school milestones, such as Ph. D. candidacy and graduation were examined for each graduate program and for gender and ethnic groups. There was substantial variation across programs and, to a lesser degree, across demographic groups. Graduation rates for foreign students were higher than those for U.S. citizens. The association between the attainment of milestones and measures of academic potential, such as undergraduate grade point average (UGPA) and Graduate Record Examination (GRE) scores, was also investigated. The likelihood of attaining candidacy or of completing a doctorate was found to bear little relation to UGPA and GRE scores. This finding is probably a result of the use of UGPA and GRE in the selection of students into graduate programs. Appendix A presents 28 tables of ethnic and gender composition. Appendix B discusses survival analysis. Appendix C contains an empirical Bayes strategy for logistic regression. (Contains 20 figures, 7 tables in the text, and 22 references.) (Author/SLD)