I have the same question for DS7 (grade 2) for when he is in grade 3, (and some more questions).

It's generally for 8th graders, right?

Does it make sense to take it for a (grade 3) kid who is at grade 8 level in one subject (maths), but much lower (say, grade 4 level) in the other subjects?

If your school gives the EXPLORE to its 8th graders, and allows younger students to take it, does it make more sense to take it at the school, or is it better to take it through a "Talent Search"? (Would scores from one be more "useful" than from the other?)

Which "Talent Searches" offer it to 3rd graders?

When is it held (once a year or more often)?