Three criteria used to differentiate public and private colleges/universities are considered, and it is suggested that these variables of financial source, control, and mission are not adequate distinctions. Although public universities receive greater shares of their income from the government than do private ones, there are difficulties in establishing an accepted cut-off point. Even if reasonable demarcation points could be established within each nation or state, it would be difficult to have a criterion that would enable comparison with other countries. A related approach is to assess the financial character of the university as consumer-oriented, even profit-oriented, or nonprofit-oriented. However, most private universities worldwide, as well as public universities, are nonprofit. Even form of control would not distinguish between universities labelled private and public, since it is common for governments to delegate substantial self-rule to public universities. The criteria of who appoints the administrators or the ultimate authority also do not offer a clear criterion to identify private and public universities. It is also difficult to distinguish different missions or clientele of private and public schools. Two alternative approaches are examined. A bottom-up approach would establish what universities called private and public actually do. The second approach, which is favored, relies more on ideal typic constructions of "privateness" and "publicness." Eventually, universities can be categorized and compared according to multiple continua. Additionally, complex system profiles can be established. (SW)