A single-subject, multiple-baseline across participants design was used to examine the functional relation between systematic instruction and the ability to complete a graphic organizer and recall facts about informational texts by students with significant development disabilities. Four high school students enrolled in an adapted academic program for individuals with intellectual disabilities participated in this study. Systematic instruction procedures included four separate trainings: (a) direct instruction on seven story-grammar concepts for social studies content, (b) guided practice on the steps for completing the graphic organizer using a modified system of least prompts, (c) guided practice on the steps for using the graphic organizer to answer comprehension questions using verbal and verbal-gestural prompts, and (d) independent practice with feedback using verbal and verbal-gestural prompts. Data were collected on three dependent variables: (a) task completion; (b) total independent story-statements; and (c) total guided story-statements, with and without materials displayed. The results of this study demonstrated strong evidence of a functional relation between systematic instruction and students' performances on the task completion and total guided story-statements, with and without materials displayed, measures. However, there was no evidence of a function relation between systematic instruction and total independent story-statements. Data collected in the generalization indicated all four students continued to perform at or near the improved level on the task completion and total guided story-statements measures after accessing texts that followed novel structures. Therefore, the findings of the current study suggest students with significant developmental disabilities were able to complete the graphic organizer in order to summarize an informational text. These results also indicate these same students were able to answer questions about texts with and without materials displayed after completing the graphic organizer. Study practical implications, limitations, and directions for future research are 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/en-US/products/dissertations/individuals.shtml.]