I've taken many an exam from these guys when applying for jobs.
Honestly....Why would any parent trust a grade on a report card? Smart parents are checking up on their children to see that they actually can read, do math, and are learning about our culture.
I think more government teachers would be honest with their grading and promotion to the next grade if they knew that most of the parents would be taking their children for private testing. If the teacher failed to teach, or the child failed to learn this would quickly show up on the private tests.
Two more highly respected private exams come to mind: the Advance Placement exams and CLEP.
The **LAST** thing I want to see are government national exams. Imagine the fun the Marxist NEA could have with that! Imagine the how powerful political groups could manipulate the nation's curriculum to teach political correctness.