Diversity and Accessibility

In chapter 36 of Instructional Design and Technology, Reiser and Dempsey explore different learners and how diversity impacts the way in which one learns, specifically as it relates to assistive technology, multiculturalism and a model of multimodal instruction. “Curriculum and instruction should include accessibility alternatives that engage students with different backgrounds, learning styles, abilities, and disabilities (Simoncelli & Hinson, 2008).”
How, as designers of IDT, do we accomplish this? Reiser and Dempsey give the analogy of quilt squares, in which all the pieces need to strategically fit into place.  How do we create good design that caters to different learners and maintain cohesive instruction?
Stay tuned as I will seek to find the answers.