My son took the STAR test in California. If it is the same STAR test, it is not useful as an assessment. My son is really good at math- he got an 87th percentile on the CTY SCAT test as a third grader, which compares you to 5th graders who take the test. On the STAR test, he got 64/65 right. He can't take the EXPLORE test since it's not in our geographical region- I assume the EXPLORE test is kind of like the SCAT test, which would give you more information.