In emergency response training, it is essential that the learners are able to apply their classroom knowledge and implement the practical and critical thinking skills they learned. A quasi-experimental methodology with a non-randomized control group and a pretest-posttest was used in this study to evaluate the training level of satisfaction as a result of using simulations in a virtual world and the effect of using simulations in virtual worlds on the learning outcomes. The results addressed the research questions by showing no significant difference in the participants' level of satisfaction and in participants' knowledge between the control and the experimental groups. Virtual worlds were found to be equivalent to traditional training methods. This study opened the door in the instructional design field for considering the integration of simulations using virtual world technology and exploring simulations in virtual world environments using a different population and/or training material. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]