This study investigated the effects of an instructional technology, a computerized graphic organizer, on vocabulary acquisition skills of students with high-incidence disabilities. Specifically, this study focused on the computerized "Real-World Connections Vocabulary" graphic organizer which was published by Dr. Edwin Ellis in 2015 and is part of the Differentiated Visual Tools Model (Ellis, Deschler, Lenz, Schumaker, Clark, 1991; Ellis, Willis, & Deshler, 2011). Although graphic organizers have been studied since they were first identified by Dr. David Ausubel in the 1960's, there is very little research regarding the effectiveness of computer-based graphic organizers and their effectiveness when used with students with high-incidence or mild disabilities and their benefit acquiring college entrance exam vocabulary knowledge, specifically the ACT exam. The purpose of this study was to examine the effects of this instructional technology tool by means of a single-subject, multiple probe across participants design. This study examined the existence of a functional relation between the computerized graphic organizer, The "Real-World Connections Vocabulary tool" (Ellis, 2015), and vocabulary acquisition. After this study, it was demonstrated that a functional relation did exist for each participant. In addition to this, a social validity survey was completed after the study which also rendered positive results regarding the use of the tool. Implication for the practice and future research are also discussed. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]