<p>I really have no idea. If they are based on those who take both tests, like I think they are, then I'd think they'd be pretty accurate for THAT population. The sample is self-selected, so you have to ask why they're taking both tests. Did they not do as well as they'd hoped on the first one? Things like that skew the data. But the colleges that develop these tables have a LOT of data at their disposal, and have been relying on that data for many years, so they must be fairly reliable. And if the school you're applying to thinks two scores are equivalent, then for their intended purpose, they are.</p>