The system of classification was developed in 1970 and first published for use by researchers outside the Carnegie Foundation in 1973. It was subsequently updated in 1976, 1987, 1994, 2000 and 2005. The original classification system (now called the "Basic System") was revised in 1997 and 2000, and underwent a major overhaul for the 2005 edition.
Classifications are organized using empirical data on colleges and universities based upon what is taught (in both undergraduate and graduate programs), the demographic makeup of the student body, the size and setting of the campus and--a classification added in 2005--community involvement.
Carnegie Classifications do not rank the quality of education at universities. Rather, their classifications are used to identify differences and similarities among institutions.
Originally, the Carnegie Classification was published in book form, but is now available only online. Listings can be customized and downloaded in CSV (comma separated values) format for use with spreadsheet programs.