Consider the following diagram, adapted from “The C-Zone”, Dr. Robert Kriegel’s book on corporate management techniques.  It describes a situation in which a person is learning new concepts or skills.

The vertical axis describes the level of difficulty for the learner, and the horizontal axis describes how proficient he is at that topic.  If a learner is in the “Panic Zone”, he is overwhelmed because his level of expertise is insufficient to master that level of difficulty. In the “Boredom Zone”, he is working on material that is too easy, given his level of expertise.

In between these two areas is a zone in which the student is comfortable with the level of challenge, given his current level of expertise.  Ideally, learning occurs within this comfort zone.

As shown in this diagram, the learning process might start with an introduction, represented by the first vertical arrow, which provides an initial look at a new level of difficulty.   Once the student bumps into the upper limit of his comfort zone, he needs to practice at that level of difficulty. This work is represented by the first horizontal arrow, in which he is gaining experience without taking on more challenging material.  If the student practices too much, he enters the Boredom Zone and finds himself doing busywork. Before that happens, he needs to be introduced to the next level of difficulty (the second vertical arrow). This process continues until the learning goals have been mastered.

The path of learning and the shape of the comfort zone are dependent on the individual student.  In the diagram to the right, a student with more ability and background experience makes larger intuitive leaps into new material and requires less practice.  His comfort zone has a steeper slope and he will clearly achieve mastery quickly.

The diagram to the left describes the learning process of a student who, for whatever reason, has difficulty in picking up new ideas and skills.  The amount of practice he needs is greater, (the horizontal arrow is longer), and it will take more effort for him to achieve mastery.

A central purpose of differentiation is to allow every student to work within his learning comfort zone and practice as much or as little as he needs to master the learning goals.