 The notion of asking teachers to become instructional designers and move beyond becoming or serving just as an instructional planner to say, we're going to cover these pages in the textbook today, I think is an important aspect as we think about 21st century learning because what it provides is the teacher's insight about the group of students that she or he is working with and thinking about what supports need to be provided for them to be successful. What we have kind of in the 20th century as a function of our technology is I would write my lesson plan and kind of teach to the middle of the class because we have one textbook, there's only so many resources and yet really what we're thinking about now as we think about diverse learners, if I got kids that aren't reading a grade level, how do I get texts that simplify, how do I build in the background knowledge that they're missing and so really these are questions about instructional design as opposed to just implementing a textbook, it's really about how do I gather the resources to make sure students learn. One way that the teachers are making a difference in classrooms today is they're using differentiated instruction and what that allows them to do is to think about different needs and to give students choice. One of the things we know about learning is that learning occurs best when there's appropriate challenge, not too hard, not too easy, but kind of right in the middle. But when I look at a student, I can't necessarily tell what's the right challenge level, that's where we need the student to engage. Differentiated instruction is a kind of a powerful construct to help teachers plan to think about how do I engage these diverse learners at the multiple levels.