I'm not so keen on using achievement scores for math placement. Consider 90th, 95th and 99th percentile kids. Say the 95th and 99th have been going to Kumon twice a week for the past three years. Bright kids schooled in math beyond grade level - they score well on the MAP math. The 90th percentile kid has just been sitting in his grade level math class, and has lots of potential, but no exposure to above grade level stuff. The 90th percentile kid gets stuck in the regular math class and is bored to tears.
Thankfully, DD9 surprised me. After getting 92nd percentile on the Fall and Winter MAP math, she got a 243 today (appears to be 98th percentile for 4th grade). I won't need to go on my special snowflake rant...this time.
