The Virtual Linguistics Campus (VLC) is the world's largest e-learning platform for linguistics. It offers fully certified linguistic classes and material for theoretical and applied linguistics. This video explains the educational model used in the VLC-On-Campus-classes: an enhanced version of the Inverted Classroom Model that uses formative E-Assessment as a bridge between the online-phase of content delivery and content acquistion and the in-class-phase of practicing. This model has been in use since 2004 and has been part of the Marburg English Linguistics curriculum ever since. A suitable name for it: "Inverted Classroom Mastery Model."