IAC's are primarily courts of mandatory jurisdiction and hear appeals from trail court decisions. Because few of their decisions are reviewed by the court of last resort, IAC's are the final arbiter of most cases. Data were obtained from appeals filed during 1986 and 1987 in four courts (Arizona, Florida, Maryland, and New Jersey). Findings revealed considerable differences in the right of appeal, particularly from nontrial criminal matters. Despite differences in jurisdiction, the four courts were similar in caseload composition in terms of underlying civil law and the most serious criminal offense at conviction. The volume of appeals filed or docketed overstated a court's actual workload, as a sizable volume of appeals were dismissed or abandoned before they reached the court for consideration. Alteration of one or more of the basic steps in the appellate process was widespread, and the time consumed by the appeals process was not uniform across courts or within courts for criminal and civil cases. In criminal appeals, the only factor consistently related to appeal time was offense type at conviction. In civil appeals, the underlying trial court proceeding was related to appeal time. The use of oral arguments did not consistently affect appeal time for either civil or criminal cases. Publishing an opinion added to the decision time for both civil and criminal appeals. Implications of the findings for improving case processing by IAC's are discussed. Appendixes contain additional information on the four State IAC's, 32 references and 52 tables