The materials for Sensorial work came from Dr. Montessori’s own observations. This material has either never been seen or never been used by the child in his everyday life, contrasting with the materials used in the Practical Life Exercises. The child will receive no new experiences through the use of the material. This was purposefully thought through in order to give the child what he knows, but might not yet realize, and to then refine his knowledge.
Dr. Montessori observed the importance of the manipulation of objects to aid the child in better understanding his environment. Through the child’s work with Sensorial material, he or she will learn make abstractions, to make distinctions in his or her environment, and the child is given the knowledge through his own experiences rather than through being told.
Sensorial Exercises were designed to cover every quality that can be perceived by the senses: size, shape, composition, texture, loudness or softness, matching, weight, temperature, etc. Because the Exercises cover such a wide range of senses, Dr. Montessori categorized the Exercises into eight different groups: Visual, Tactile, Baric, Thermic, Auditory, Olfactory, Gustatory, and Stereognostic.
Visual Exercises: the child learns how to visually discriminate differences and similarities between objects.
Tactile Exercises: the child learns through his sense of touch. Although the sense of touch is spread throughout the surface of the body, the exercises given to the children are limited to the tips of the fingers. This allows the child to really focus on what he is feeling, through a concentration of a small part of his body.
Baric Exercises: the child learns to feel the difference of pressure or weight of different objects. This sense is heightened through the use of a blindfold.
Thermic Exercises: the child works to refine his sense of temperature using tablets or bottles made of materials with different capacities to conduct heat. Dense minerals such as stone, steel or copper conduct heat very well and feel cool to the touch whereas porous, organic, materials such as rubber, wood, or felt conduct heat poorly and feel warm to the touch.
Auditory Exercises: the child discriminates between different sounds and will become more sensitive to the sounds in his environment.
Olfactory and Gustatory Exercises: the child is given an introductory exercise in smelling and tasting. The child works to distinguish one smell from another or one taste from another and then can then take these senses, and apply them to other smells or tastes in his environment.
Stereognostic Exercises: the child learns to feel objects and make recognitions based on what he feels. Dr. Montessori discovered that when the hand manipulates an object, an impression of movement is added to the touch. Such an impression is credited to a special muscular or “sixth” sense, which permits the impressions to be stored in a “muscular memory”. This memory recalls movements that have been done before.