Dr. Maria Montessori (1870-1952) was the first female physician in Italy. She spent most of her life studying and aiding the development of the individual from birth to maturity. Since education is a vital part of an individual's formative process, she studied methods that would help children develop their mental abilities. She saw these methods not merely as an aid to cognitive development, but as an aid to life. She discovered that children pass through levels of development, and that at each level they have different sensitivities, or sensitive periods, for learning and developing. She also noticed that children are naturally curious and engage in much spontaneous activity. She observed that by providing children with an appropriate prepared environment, which would direct their spontaneous activity, adults could help children to take advantage of their sensitivities. The Montessori classroom materials and activities are designed to help the child learn by doing. It is considered essential that children learn concepts by means of manipulating concrete materials. Therefore, computers are not used for teaching.