Decision Support for Option Awareness in Complex Emergency Scenarios Mark S. Pfaff Indiana University – Indianapolis Jill L. Drury, Gary L. Klein The MITRE Corporation Loretta D. More The Pennsylvania State University ABSTRACT To enhance the decision support of emergency responders, we are examining the ability of decision space visualization tools to enhance option awareness and support more robust decision making. The current study extends prior work to detail the impact of the decision space information provided to users, relating the correctness of decisions to the levels of complexity represented in the events and the affordances for understanding alternative actions. This research provides further insight into the value of decision space information and option awareness for users working in complex environments. Keywords: Decision making; emergency management; situation awareness INTRODUCTION Emergency response is an especially challenging domain for decision support, as life-or-death decisions must be made very quickly, often with high levels of uncertainty in the information available about the situation. While model-based decision support tools have been used extensively in emergency planning, their high sensitivity to input conditions has limited their utility during ongoing emergency events. Because of the sensitivity of critical decisions to conditions outside of the