Experimental sections?

<p>I'm not really understanding this whole "experimental" section business. So far I've gathered that only the Math and CR sections can be experimental. </p>

<p>So, did EVERYONE who took the SAT get an experimental section? Either 1 math or 1 reading? Or did only some people get experimental sections and got 2?</p>

<p>I'd appreciate if someone could be kind enough to explain this to me.</p>