Melanie, at San Francisco State our HyFlex courses are quite varied. We follow our academic Senate policy definition which allows a lot of individualization by faculty for specific high flex classes.
“HyFlex courses are class sessions that allow students to choose whether to attend classes face-to-face or online, (e.g., synchronous, asynchronous, bichronous).”
Our two fundamental defining characteristics for high flex course are, 1) that there is a face-to-face and at least one online option available for students, and 2) that students are the ones making the choice about their participation patterns for every session of the class. We follow these requirements in all of our HyFlex courses.