After experimenting extensively with a large assortment of classroom aids, e.g., blocks and rhythm instruments to stimulate the oral expression of preschool children, it was found that far less language expression resulted than had been anticipated. When those experiments which had been mildly successful were evaluated, it was decided that young children needed to learn how to look at pictures, what to look for, and what the whole and the parts of objects were called. Since learning began with perceiving, preschool children seemed to require large numbers of guided perceptual experiences in which they could see, hear, and feel the materials while their attention was being called simultaneously to the differentiating characteristics of each object. Relative success was then achieved in stimulating oral expression with such classroom materials as blocks, photographs, magnets and shapes, and a terrarium because the children's perceptions had been carefully guided toward the uniqueness of each aid as the peculiarities were labeled and discussed. These experiences seemed to indicate that all classroom materials should be introduced to young children on the perceptual level primarily as language materials in which the clues are used and reused to reinforce their context. (JB)