The researcher concluded that teacher training was of ultimate importance for a successful outcome of differentiated instruction in sixth-grade inclusion classes. Students with special learning needs whose learning depends largely on student-centered teaching are more likely to show academic advancement when instruction is differentiated to their needs. Most students with special needs thrive when met with a challenge that can be achieved. Differentiated instruction can provide such a challenge to all learners. [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.]