This study examined the effects of manipulating the modality (text-only, voice-only, voice+text) of a tutorial and restriction (restricted vs. unrestricted) of a simulation's interface on retention and transfer of tutorial content. The tutorial prepared novice students to use Packet Tracer, a simulation developed by Cisco that teaches network engineers how to build and troubleshoot computer networks. Retention was measured using a multiple choice test whereas transfer was measured using an assessment embedded within Packet Tracer. An interaction was found between modality and restriction on the Packet Tracer transfer test. When Packet Tracer's interface was unrestricted, students who received the voice-only tutorial performed significantly better on the transfer test than students who received the text-only tutorial. This finding is consistent with the cognitive theory of multimedia learning and previous research on modality effect. However, this is also an original finding because previous research has not examined the interaction between a tutorial's modality and the restriction of a complex simulation's interface. This study addressed relevant instructional technology design questions, such as how to design tutorials for complex simulations and what effect restricting a simulation's interface has on retention and transfer for novice students. [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.]