The key principles are:

• A differentiated classroom is flexible: teachers and students understand that there are many classroom elements that can be used to promote individual and whole-class success, such as:
  
  • time
  • materials
  • modes of teaching
  • ways of grouping students
  • ways of expressing learning
  • ways of assessing learning.
• Assessment and instruction are inseparable: the teacher views everything that a student says or does as useful information to understand the learner and craft their effective instruction for that learner (differentiation of instruction stems from effective and ongoing assessment of learner needs).
• All students participate in ‘respectful’ work: each student needs to be involved in challenging tasks that are equally interesting and engaging, to offer equal access to essential understanding and skills.
• Students and teachers are collaborators in learning: the teacher studies their students to ascertain what works and what doesn’t work for them and continually involves students in decision-making about the classroom (as a result students become more independent learners).
• The teacher uses flexible grouping options: they plan student working arrangements that vary widely and purposefully often over relatively short periods of time, for example, whole-class, small group and one-on-one arrangements are used (the flexible grouping of students helps ensure access to a wide variety of learning opportunities and working arrangements).
• The teacher focuses on the essentials: they provide clarity about what is essential for students to know, understand and do.
• The teacher modifies content, process and products: they find key opportunities to meet learners where they are ‘at’ in order to propel them forward in knowledge, understanding and skill.

Note: it is not necessary to differentiate everything all of the time.

Those elements may include time, space, groupings, materials, modes of presentation, modes of investigation, resources and instructional strategies.

Flexibility involves the teacher searching for solutions to the inevitable problems and tensions that arise when teaching complex content to a variety of students.

• The teacher knows what to do next when they recognise where students are in relation to the learning intentions/goals.
• The teacher is primed to teach more effectively if they are aware of the students’ needs and interests.
• Pre-assessment informs the teacher of the student status (knowledge and skill) in relation to upcoming learning intentions/goals, student interests and the students’ preferred ways of learning.
• On-going assessment (assessment for and as learning) throughout the lesson sequence/unit sharpens the teacher’s sense of what is working and what is not yet working for all the students in the class. It enables the teacher to continue working with students in ways that target their particular strengths and needs in light of important learning intentions/goals.
• Summative assessment (assessment of learning) should be designed to maximise student opportunity to demonstrate what they have come to know, understand and be able to do as a result of the lesson sequence/unit. It can also ‘feed forward’ to the next lesson sequence/unit so that the teacher is continuously gathering data on student growth and refining instructional plans based on the data.

The teacher’s goal is that each student finds their work challenging and interesting, and grapples squarely with the knowledge and skills which give them the power to understand, apply and progress to the next learning stage, most of the time.

Differentiation does not presume different tasks for each student, but rather just enough flexibility in task complexity, working arrangements and modes of learning expression that varied students find learning a good fit much of the time.

Classrooms are more effective and inviting when responsibility for their operation is shared by all members of the learning community.

Students hold pivotal information about their likes and preferred ways of learning.

Students can learn to make choices that enhance both their learning and their status as a learner.

• work in similar readiness groups with peers who manifest similar academic needs at a given time
• of mixed readiness work together in settings that draw upon the strengths of each student
• work with classmates who have like interests
• of varied interests cooperate towards completing a task that calls on all their interests
• work with those who have similar learning patterns (a group of auditory learners listening to a taped explanation)
• work with students with varied learning patterns (an analytic student and a practical student) to complete a task
• work with whoever is sitting beside them
• count off into groups
• draw a partner’s name
• choose who they work with.

• provides a compass for a curriculum that both engages their students and promotes understanding
• develops work that focuses on what matters most
• provides a basis for extending the work of students who are advanced and scaffolding the work of students who require extra support.

This is done by providing opportunities so students can work with content and products in sense-making learning experiences that are responsive to the students' readiness, needs, interests and best modes of learning.

In doing this, teachers maximise the opportunities for success for each learner.

• Tomlinson, C. (2006). An Educator's Guide to Differentiating instruction. USA: Cengage Learning.
• Tomlinson, C. A., & Allan, S. D. (2000) Leadership for Differentiating Schools and Classrooms. Alexandria, VA: Association for Supervision and Curriculum Development.