Another observation of Dr. Montessori which has been reinforced by modern research is the importance of sensitive periods for early learning. These are periods for intensive fascination for learning a particular characteristic or skill, such as going up or down steps, putting things in order, counting or reading. It is easier for the child to learn a particular skill during the corresponding sensitive period than any other time in his life. The Montessori classroom takes advantage of this fact by allowing the child freedom to select individual activities which correspond to his/her own periods of interest.