Although widely used, cohort-based graduation and dropout rates are subject to many limitations. For example, the GRS restricts the denominator to first-time, full-time students, which may represent only a small fraction of beginning students at institutions that enroll large numbers of part-time students and beginning transfers. Including these students in the cohort allows for more completeness, but causes further problems because part-time students have differing credit loads and transfer students bring in wide ranging numbers of previously-earned credits. This renders fair comparisons difficult because, unlike the first-time full-time population, not all subpopulations are starting from the same baseline.
Graduation data, such as that produced by IPEDS, thus penalize certain types of institutions since they do not account for differences in entering students’ characteristics or resources available to the college. Graduation rates also reflect admission standards, the academic strength of the enrolled students, and the resources institutions devote to instruction, to remediation, and to retention. Because of this heterogeneity in student types and institutional missions, any increase in the production of graduates (either through increased graduation rates or expanded enrollment) will likely happen at lower ranking institutions; highly selective schools are not going to change and are already operating at capacity.
These are legitimate issues, but if those were the only ones, a case could still be made for the public policy value of graduation rates, with appropriate caveats attached. The primary reason to de-emphasize IPEDS graduation rates in public policy is that, when used in the aggregate for a whole state or a group of institutions, the information that many believe is being conveyed simply is not. To illustrate, Table A.1 contrasts the average IPEDS graduation rate for community colleges nationally with the more comprehensive picture of student persistence and attainment from the Beginning Postsecondary Student (BPS) Survey. The data are for the same cohort of students; IPEDS includes all students who entered as full-time students at community colleges in fall 2003. The BPS results are from a comprehensive survey of a sample of the same students. As expected, the same-institution graduation rate is within the survey’s margin of error, at a little over 20 percent, but there is also much more information about what happened to the other 80 percent.
A number of institutions have taken steps to produce additional statistics that give greater context to graduation rate information. The Minnesota’s state college system maintains an “accountability dashboard”1 for each of its campuses. Beyond the number of students completing degrees), its variables indicate, for example, the condition of facilities and pass rates of graduates taking professional licensing exams. The California State University system attempts to approximate the value of degrees, posting online the median starting and mid-career salaries for graduates of each campus, as well as their average student loan debt.2
1See http://www.mnscu.edu/board/accountability/index.html [July 2012].