Better analogy is giving students poor grades for not participating in P.E. class well. I recall HS gym class having a few weeks focusing on football - totally

Better analogy is giving students poor grades for not participating in P.E. class well. I recall HS gym class having a few weeks focusing on football - totally presuming that everyone knew the rules; I garnered penalties for the team for merely twitching on the line just before the snap ("whadayamean called for 'movement' because I moved my foot one inch?"), and didn't figure out what a "down" was until my mid-twenties. Never occurred to the coach that some students had no idea what the rules were, yet the grade likely depended on how well they fulfilled those rules. You're presuming all introverts already know how to speak before & work with groups. Many don't!