Using a set of scenarios derived from actual evaluation studies, this simulation study examines the reported influence of evaluation information on decision makers' potential actions. Each scenario described a context where one of three types of evaluation information (large-scale study data, case study data, or anecdotal accounts) is presented and a specific decision needs to be made. Participants were asked to indicate which type of data presented would influence their decision making. Results from 131 participants indicate that participants were influenced by all types of information, yet large-scale and case study data are more influential relative to anecdotal accounts; certain types of evaluation data are more influential among certain groups of decision makers; and choosing to use one type of evaluation data over the other two depends on the independent influence of other types of evaluation data on the decision maker, as well as prior beliefs about program efficacy. (Contains 6 tables, 1 figure, and 3 notes.)