In higher education collective bargaining litigation, the determination of which academic personnel will be included in bargaining units has resulted in many contradictions. Supervisory and managerial personnel have been included with faculty in some schools, and excluded in others. Law and medical school faculty, support staff, and part-time employees have encountered the same treatment; being welcomed among the faculty units at some institutions and categorically excluded at others. These confusing distinctions have occurred in both public and private sectors and afflict multi-campus schools as well as single campuses. In reviewing these cases, however, certain criteria can be distilled that coordinate these seeming contradictions. The primary criterion at the base of unit determination is "community of interest," a concept developed in the private industrial sector. The list of criteria for unit determination of the National Labor Relations Board includes similarity in earnings, benefits, work performed, and job skill requirements, as well as the desires of the affected employees and the institution's history of collective bargaining. There may, of course, be more than one appropriate unit, but only one is chosen; and both sides are tempted to include those whose union views are similar to their own. Each diverse group represented in a unit must be adequately represented. Relevant cases are cited. (DR)