There are two more points I'd like to make.
First, I don't want anyone to go away with the impression that a Montessori school allows the children to run wild all day long. Quite the opposite is true. At our school/daycare, there was indoor playtime, circle time, school work time, outdoor playtime, lunch time, and guest speakers/performers' time. If it were indoor playtime, the children were required to stay indoors, but allowed to work with any material in the classroom they wished. The classroom had Montessori manipulatives as well as toys (which is not typical of a more stringent Montessori.) The Legos or Marble Run or other toys could be used only during play time. If a child were too antsy during circle time, they might be invited to find a quiet educational activity of their choosing so that the rest of the class could focus on circle time.
In searching for a daycare for my first child, I toured two daycares back to back. The first was a Learning World (chain), and the place was very chaotic, children running everywhere and loud! When I walked through the facility, the toddler class teacher (young, ill with a cold and coughing all over the children) spent the majority of the 10 mins. I observed her yacking on the phone and ignoring her young students. I was horrified.
The Montessori school was a night-and-day difference. All classrooms (Infant through 1st Grade) were calm and quiet. In the infant room classical or other soothing music played, and the babies were on the floor and so were the teachers, playing with them. Some students worked alone or with a classmate or teacher. The teachers praised the students a they worked and listened to any of the children's concerns. No raised voices, no one upset, no one running rampant. In the toddler class the teachers had just set a low table with snacks, and these one year olds calmly walked over and took their seats, ate their snacks without making an enormous mess, then cleaned up their place setting and pushed in their chairs before heading to play outdoors. I was stunned that children so young could be so orderly and self sufficient! They were even taught how to put their coats on by themselves by laying it out on the floor and sliding their arms into it.
We've bumped into three of DS' former classmates from daycare in the past year, and two of them are in the gifted program for our school district, and my son and the other child are both ahead of the curve in regular classrooms. I do believe the Montessori program gave these kids an interest and love of learning, and basic tools to help them throughout their schooling.
The focus of Montessori really is to make the child as independent, self sufficient and
self disciplined as possible. While I like the general idea, and agree with most of the principles, I do not agree with all. For instance, strict Montessori teaching requires that a teacher not comfort a child who's been injured, reasoning that the child will learn to self-comfort and be more independent. They also do not show affection unless the child asks/invites it. Personally, I'd rather my child had a teacher who showed affection and gave comfort if he was obviously upset.
Secondly, the comment by a PP with two acquaintances who did not learn left from right in a Montessori setting is just mind-boggling to me. I think I learned my left from right at home, not at school, but I never attended a preschool. I assure you my older son (nearly 8yo) knows his left from his right, and I'm fairly sure my younger son (4yo) does as well. I doubt a
lack of knowledge has to do with Montessori teaching. In fact, I have seen a wooden puzzle in DS4's (more strict Montessori) classroom that shows left and right hands and counts the finger of each.
I would encourage anyone interested in a Montessori school to read up on Maria Montessori's philosophy and methodology, paying particular attention to what you agree with and do not agree with or have questions about. Then take your questions to a school and find out how strictly they follow those, and how and why. I would not discount a school just because it did not adhere strictly to Montessori teaching. Very few if any can follow Montessori 100% due to state laws. I would not be interested in a school that followed strict Montessori principles. What matters to me most is that their principles and practices align with what is important to me for my children.