You can look at various charts with national norms, but what I find is most helpful is where the RIT score falls within your DC's school. That is, does your school release a report at a school board meeting about the RIT scores for each grade or student population? I have found this type of information to be the most helpful, since our school likes to boast that its students are above the national average (which is true). This way, even in a "high performing" school, you will know whether your student is scoring high, even within his school.
HTH!
