Lily:
Google 'nation deceived' and check out the U. Iowa program on gifted education. The Nation Deceived report, which you can get gratis, provides a whole set of well-documented, well-argued, authoritative, data-based arguments in favor of acceleration, which can help you to elevate the discussion with your school administration above that of an 'us-them' disagreement. If you have resources for the substantial testing required, ask them to use the Iowa Acceleration Scales as a relatively objective determinant of your child's preparedness for acceleration.
I thinks its also useful to argue the costs and risks to the child of not accelerating, in counterpoise to the costs and risks of accelerating, which is where schools often seem to place emphasis. These risks include that of undermining the child's enthusiasm for learning and his/her work ethic (which is critical to long-term educational success).
One parent posting on this forum in a similar situation said that they had agreed with the school that acceleration entailed some risks, but that they were approaching them with open eyes and would put in the extra effort from their side to manage these risks if they manifested themselves.
Another good book resource in this area is Re-Forming Gifted Education, by Karen Rogers.
The bottom line, in my mind, is that if the child is not being substantially challenged, he or she is not being educated. Education is the mission of most schools.
