The Montessori Foundation has performed a great deal of reserach on the topic. In 2006, they concluded that at the end of the third year, Montessori kindergarteners "were significantly better prepared for elementary school, outscoring their peers in reading and math skills. They also tested better on 'executive function' the ability to adapt to changing and more complex problems. This is an indicator of future school and life success."
Some additional research findings:
- Montessori students scored 10 - 20 points higher on the California Achievement Test compared with students in traditional classrooms.
- Minority students enrolled in a Montessori program scored higher on self-concept, mathematical and geometric concepts, vocabulary recognition, attention strategies, and general intelligence.
- 75% of low SES children who attended a Montessori preschool in Cleveland, Ohio, scored above school norms on the California Achievement Test.
- Increases in attention strategies, general intelligence, and academic achievement occurred over time by Montessori students from all socioeconomic levels.
As they say, the proof is in the pudding.