Correction factors are when you take the actual, uncorrected, numbers and run them through a formula. basically, SAE takes your uncorrected numbers and determines what they would be at 1 atmosphere of pressure and 60* F...and some humidity. This way, you can have a standard comparison for values around the country. For example, my numbers...which is prolly the thread you are talking about. I put down almost 500 hp. Well, most of that was because it was only 44* in the shop and 9% humidity. The correction says that if it were 60* and the pressure was 1 atmosphere, then I would have made 454. This way, someone in colorado can compare his numbers to someone in louisiana
and see how close they are since colorado is not good air for power due to it being so thin.
I don't know the exact details to the formulas, but I know each applies different values to arrive at a common number. It is mainly for a basis of comparison. Uncorrected is what you actually put down on that day. SAE, STD, and the other factors are what you make in the conditions of the correction.