Classroom structures should be designed to respond to the needs of every student
Because students have different ways of learning, every student should be able to learn in the way that is optimal for him. Because students learn at different rates, they should be able to pursue mastery at the rate they are capable of, not one defined by the needs of the class as a whole.
The student (with some training) knows best
In general, it is appropriate and effective for students, rather than teachers, to steer their own learning. Internalizing the decision-making in the learning process is a worthwhile skill, regardless of the content being learned. It is a life skill that is useful not just in high school and college, but in any job worth having.
Differentiated instruction is what teachers do; differentiated learning is what students do
The difference is whether the student has agency and ownership of the learning process. Who makes decisions truly matters.
Not every student should be expected to master the same amount of content
Some students will always learn more than others. No matter what standards we impose, this has always and will always be true. No one should be penalized for that fact.
Students who learn more quickly should have more challenging material available
Enrichment activities are necessary so that students who have mastered the essential learning goals will be able to continue pushing themselves at an appropriate level of challenge.
Feedback steers differentiation
In order for a student to know what to do when there are options available, he needs feedback that explicitly shows his status in mastering the material.
Feedback steers the learning sequence
Feedback is how you know when the divergence in student understanding is becoming significant and must be addressed. A mechanism for differentiated learning is necessary at every juncture where such divergence occurs.