The Sensorial Materials are materials used in the Montessori classroom to help a child develop and refine his or her senses. Like many other materials in the Montessori classroom, the sensorial materials have what is called "control of error", meaning that the child not only works with the material, but has a way to check their work rather than seeking out the Directress if they have a question on whether or not they did it right. This is done to help promote independence and problem solving on the part of the child.