I read something when they first started with the crafting, it said something to the effect of, each class is generally better suited for one particular form of crafting. If you look at what Alterego wrote, you can pretty much figure it out. The stats that are your power pool will show you which craft your class is most suited for, which ends up making sense, i.e. a tanks power pool stats are str and sta, they are best suited for crafting armor which is a big concern of a tank.