Our school uses CTP 4. Supposedly, it is designed for "high performing" schools, and is thought to be more challenging than ITSB. There's a layperson's interpretation of the differences in this article from a district in New Jersey that switched to CTP4.

http://newstranscript.gmnews.com/ne...o_identify_math_skills_needing_work.html

The example given here is that ITBS asks for the next number in a sequence. CTP4 asks "which of the following is not part of the sequence." There is a little more abstraction I guess, and from a grade-schooler's perspective, it's supposedly more challenging.

i know of one public school system that switched from ITBS to CTP4. Their mean scores were way above average on the ITBS, and dropped below the 50th percentile for national norms on the CTP4.

The CTP4 scores are reported both as a percentile of national norms and as either private, urban or suburban schools (or something like that - don't quote me).

There are verbal and math sections, and I think a writing section starting at a certain grade level IIRC. I would think your school could give you more info.

Hope that helps.