Compléter Actividad en linea #2 Version en ligne Grupo The Powers par Eduardo Alfonzo 1 As a doctor , Montessori chose pediatrics and psychiatry as her specialties . While at her medical - school alma mater , Montessori treated many poor and - class children who attended the free clinics there . During that time , she observed that intrinsic intelligence was present in children of all socio - economic backgrounds . Montessori became the director of the Orthophrenic School for developmentally disabled children in 1900 . There she began to extensively research early childhood development and education . Her included the studies of 18th and 19th century French physicians Jean - Marc - Gaspard Itard and Édouard Séguin , who had experimented with the capabilities of disabled children . Montessori began to conceptualize her own method of their educational theories , which she tested through hands - on scientific observation of students at the Orthophrenic School . Montessori found the resulting improvement in students' development remarkable . She spread her research in speeches throughout Europe , also her platform to advocate for women's and children's rights .