In Montessori classrooms the materials are also known as Didactic Materials. In a typical classroom they may be referred to as manipulatives. Didactic materials are unique in that not only are they manipulative but they must include these criteria:

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• They isolate one point of interest or concept.

• They lead students from a concrete example to an abstraction.

• They lead students from an unknown concept to a known one.

• They are made precisely, and are to be of natural products and kept in excellent condition.

• They are to be presented on the shelves in a way that they ‘call to the child’.

• They are presented first by the Directress often using a three period lesson to model how the material will be used by the student when practicing.

• The student is to practice and then through repetition show mastery.

• They have a ‘control of error’ which allows the student to learn from use rather than the teacher.

• The directress observes the student using and practicing material and then can determine the student’s level of independence and mastery authentically.