This applied dissertation was designed to evaluate alternative and effective forms of instruction for young students with autism spectrum disorder. The researcher examined and compared the difference in the instructional formats of 1:1 discrete trial teaching and small-group discrete trial teaching. Targets were chosen in receptive language and preacademic concepts, and differences were compared based on skill acquisition, speed of acquisition, generalization, and maintenance of skills. The participants engaged in the 8-week intervention phase of the study by following an alternating treatments design schedule during their designated center time rotations in the classroom. All participants engaged in 1:1 discrete trial teaching and small-group discrete trial teaching sessions throughout the intervention with their own specified targets in receptive language and preacademic concepts. An analysis of the data revealed that skill acquisition varied between participants and between instructional formats. All participants gained knowledge and skills in the targets chosen, although an important element of the results displayed different results. One participant benefited more from small-group instruction, another participant did better with 1:1 instruction, and the third participant had extenuating circumstances that may have affected the results. Ultimately, both instructional formats of 1:1 and small-group were determined to be effective forms of intervention when working with students with autism. [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.]