Are the mechanics for PSE burst documented anywhere? Do people generally have a good idea of how it works?

I've noticed that when there's a PSE Burst (and Cross Burst) that I get tons and tons of exp. So much that it makes normal gameplay for exp seem kind of pointless -- if there's a way to trigger PSE Burst semi-reliably, then I would probably prefer to be spending all of my time trying to do that.

Are there any PSE Burst experts who want to chime in?