I noticed myself (at the Open House) urging prospective parents to visit the classrooms in action. Last year, when I visited the school for my observation time, the deal was sealed for me. I watched children deep in concentration, uninterrupted...doing what they were interested in that day. I observed several children interested in puzzles and working together. I also saw 2 kids decide that it was snack time and fix themselves some yogurt and fruit. A few others were working independently on practical life works.
The more I learn about Montessori, the more I love it.