The study of the consequences of evaluation, or more specifically of evaluation use or utilization, represents a significant portion of the body of research on evaluation. Much has been written on the evolution of the multidimensional concept of evaluation use, most recently the examination of consequences of evaluation that are not a function of evaluation findings or recommendations, but rather of the "process" of evaluation in its own right. Conceptual and theoretical work on process use has begun to spark empirical research that is increasing understanding and use of the concept in informing evaluation practice. The authors' purpose in this article is twofold: (1) to consider how the construct of process use has been operationalized in empirical research examining process use directly or indirectly; and (2) to describe the types of research that have been carried out, with an eye to developing an agenda for ongoing research in this area. Although process use is present in conceptual literature on evaluation use, it has thus far seldom been put to empirical test. As evaluation theorists call for more research on the influence of evaluation on individual-level cognitive processes and interpersonal behaviors and as process use moves from being seen as a positive, incidental consequence of evaluation toward a goal evaluators aim to achieve through their approaches and methods, the need to provide empirical support for the concept becomes more pressing. This article first describes the methods used to identify empirical research concerned with process use and then describes sample studies. It is then followed by an analysis of these studies in terms of their operationalization of process use. The authors conclude with some thoughts on an agenda for ongoing research. (Contains 1 figure, 3 tables, and 2 notes.)