and the limitations of the model and uncertainties in the data must be conveyed (Ferguson et al., 2003).

Exercises are believed to be effective in enhancing preparedness and are widely used by local, state, and national disaster response agencies (GAO, 2001). The emergency and disaster response field’s assumptions that exercises work to improve preparedness have been reinforced by experience that has suggested a link between exercises and good performance in an emergency or disaster (FEMA/EMI, 2003). According to FEMA’s Emergency Management Institute (2003), exercising reveals flaws in planning, clarifies roles, improves individual performance, and tests and evaluates plans, policies, and procedures. Moreover, exercises have become an institutionalized strategy for planning in homeland security. In fact, the DHS HSEEP materials assert that exercises “provide a risk-free environment for jurisdictions to assess if they have the plans, policies, procedures, resources, and agreements in place to enable homeland security personnel to perform critical tasks required to prevent, respond to, or recover from a terrorist attack” (DHS/ODP, 2003).

Exercises contribute to preparedness by fostering relationship building; by providing a context and tool for training; and by providing a method for evaluating performance. The use of exercises for training may originate in the military experience, but they are conducted as part of preparedness in a variety of contexts, from the nuclear plants required by the Department of Energy to use exercises to prepare for the possibility of an accident, to local firefighters training to deal with major fires or with natural disasters, to regional exercises required by FEMA to respond to hazardous materials (HazMat) and natural disasters.

When exercises are conducted in order to educate, train, or develop interorganizational and interjurisdictional relationships, the underlying assumptions may be easily validated. Disasters are complex events that require many different types of responders; therefore, having partnerships is preferable to working in isolation. Furthermore, some level of organization and coordination is essential to help avoid chaos; rehearsing processes may lead to smoother functioning of complex response systems, and in the event of an emergency, for example, a smallpox attack, having personnel that possess certain knowledge and skills (e.g., smallpox diagnosis, vaccination, and search and containment) is better than having personnel that did not receive such education and training. Exercises that test communication across jurisdictions or test certain skills and processes may provide some indication that certain things are likely to work well in a disaster.