Yeah, basically. A is Area and D is Defect density. As area in increases, you always have more defect opportunities, so you have to drive D down to maintain same yield. Notice all these models are stochastic and are basically just penalty functions that penalize increasing AD in different ways. Inceasing AD is always bad for yield. You would have to pick the best model to fit your data. But, it doesn't mean very much. Say the Seeds model is the best fit. That means just that, nothing more....