Choosing the best preschool for your child is a decision many parents agonize over. I know that I did. In writing this series I took my 3-year-old daughter, Mirai, to each of the schools to observe her behavior.

I was expecting Mirai to exhibit clear preferences, and I was amazed, truly amazed, when she didn't. She immediately found the strong points of each school we visited, and a frequent refrain in the days following each excursion was "Let's go back!" What my daughter was picking up on in each of these places was the fact that the teachers and children made her feel welcome.

As I examined each school, I took note of the quality and comfort of its indoor and outdoor facilities, the nutritional value of its snacks and lunches, whether emphasis was placed on activities inside the classroom or out, the proximity of local parks, and whether the teachers were creative and innovative.

I also took note of the ratio of teachers to students and how the teachers managed their charges. In Tokyo, it is not unusual for preschool classes to contain as many as 25 children. Preschoolers can behave in unpredictable ways, and though it's natural for parents to prefer small classes, in Tokyo they must be prepared to pay a substantial premium for it.

Keep in mind that loosely supervised doesn't necessarily mean chaotic. To make big classes work, children can be taught to protect and learn from each other at a remarkably young age. Giving them responsibility helps this process.

I noticed that my daughter bypassed my rational concern about "getting lost in the crowd." With each school we entered, she reacted to the new environment from the heart. Children know when they're being made to feel welcome. Of course they are drawn to interesting new playthings, creativity, song, dance and free exploration, but more than that, they need to feel safe to interact with other children and teachers.

The four schools covered in this series each followed different educational philosophies, but all shared this common belief: "Preschool children learn through play."

If you've chosen with your child's best interests at heart, your child will let you know it. Children who are filled with joy, learn with joy.