Compare to other boards of school, what advantage does private school have?
There are number of reasons that parents choose to send their kids to private school that you may be interested in reading more about here: http://www.ourkids.net/school/benefits-of-private-schools.php - a few of the main reasons include smaller class sizes, a close-knit community environment, access to more extracurricular activities and educational philosophies, and more parental involvement.
If you are interested in more of the public vs. private debate, you may like to read this article: http://www.ourkids.net/private-schools-versus-public-schools.php
You may also be interested in why parents choose to send their children to private school here: http://www.ourkids.net/school/benefits-of-private-schools.php
The upcoming Private School Expos are also a great opportunity to meet face-to-face with a number of different private schools all in one place as well as attend information seminars. Many parents find this helpful to learning more about private schools and narrowing down their choices: http://www.ourkids.net/expo/