“Dear Dr. DOE, is one factor at a time OK when my continuous factor settings depend on my categorical levels?” JMP’s Don McCormack once again assumes the identity of Dr. DOE to answer this question, a real-world one he recently received from a JMP user in the chemical industry. In a simple experiment where factor A is categorical and B continuous, they wondered, what happens when the B settings depend on which A level is being used? The good news is you don’t need to set up a separate design for each A level. JMP has a better way. Watch as Doctor Dr. DOE takes you through the steps needed to build such an experiment and how best to analyze the results.