The Iowa Scale is the textbook I was referring to- recognized this once I saw it referenced in Cricket2's post. I read the Amazon reviews and other reviews and it seems to be a very comprehensive guide on placement. Grade acceleration is a decision with serious consequences for your children. I think investing in this book and then following its guidelines on testing and placement would result in the best possible decision you could make. If you use the book and the school fights you on what placement you want, you can use the book as a reference tool to substantiate your request. The book is geared towards educators- so I think it would be difficult to argue about placement if you follow their recommendations. I believe the book will take you through an assessment of all areas of your children's lives so that every aspect is considered before you find the recommended placement.