MDM 2/e was created for an early version of VUMIE. As we refined its content, changes were made that rendered MDM 2/e obsolete for our current version of the software. So, we created a new edition of the lab manual to better reflect the improved version. MDM 3/e matches the content of the software in ways MDM 2/e does not, and provides better guidance for helping students master the software quickly and easily. We find that instructors and students avoid confusion and inconsistencies by sticking with MDM 3/e. And so, for that reason, we have stopped offering MDM 2/e for users.