I fancy myself a pretty good sadist when it comes to generating shame and self-loathing in the tardy. If I spot a repeat offender in the hallway before class, and find that they’re not in attendance even after I’ve given them a comfortable buffer of time, I might push trashcans and desks in front of the door, constructing something of an obstacle course between the doorway and the desk so that they realize they can’t sneak into the room unnoticed. In fact, all eyes turn upon them, turning what would otherwise be my lone steely glare into a collective gaze that beams upon them like so many hot spotlights. I don’t even pay attention to them, and just continue my teaching unabated.
Other tricks I’ve tried include: calling on the latecomer to answer a question the second they walk in the door, having students put their book bags on every remaining open seat, and even leaving a note on the board that says “we’re outside” while promptly canceling class altogether. Well, okay, I haven’t really done all these things. But I’ve thought about it, and they’re all in my bag of tricks if I ever get desperate. I have, however, threatened to extend class for as many minutes as it took for the last arrival to enter the room. –Mike Arnzen –Ambush the White Rabbit (Inside Higher Ed)