Since the establishment of the first volunteer fire brigades in the United States, firefighters have lost their lives in fire fighting operations at emergency incidents and live-fire training activities. While there are various reasons for these firefighter deaths and injuries, the United States Fire Administration (2002) reported that many of them occurred as a result of ineffective and/or incorrect decision making by fire ground incident commanders (ICs). The problem is ineffective and/or incorrect decision making by fire ground ICs has resulted in firefighter deaths and injuries at emergency incidents and live-fire training activities. Fire ground IC training programs have remained unchanged, consisting of traditional classroom lecture followed by live-fire training evolutions where firefighters are exposed to extremely hazardous conditions and at a very high risk of personal injury. IC training programs must be adapted to focus on proper decision making and on teaching current and future ICs the proper incident mitigation techniques, while reducing the risk to firefighters and lessening municipal liability. Scholarly research has established that fire ground ICs use naturalistic decision making (NDM) processes, based upon their knowledge and experience, to manage strategically and tactically their available resources during incident mitigation activities. It was predicted that computer-based simulation can be used to create realistic and dynamic virtual environments where participants realize gains in knowledge and experience without the associated safety hazards of live-fire incidents or training. The purpose of the study was to establish a statistical correlation between a computer-based simulation training program and increases in the decision making efficiency/accuracy of fire ground ICs. A Nonequivalent (Pre-test/Post-test) Control-Group Design was employed with pre-test data used as a baseline to compare the post-test data of the treatment group and comparison group after approximately one year of simulation training. The results of the statistical analysis validated the research study hypothesis by establishing a correlation between the computer-based simulation training program and a positive effect (increase) in the efficiency/accuracy of decision making of fire ground ICs in the simulated environment. A valid supplement to traditional IC training programs is now available which can enhance both student decision making and their safety. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]