Problem (hypothetical, not a measured case): in a shared household with staggered schedules, small maintenance tasks — rinsing the compost pail, putting recycling out, clearing the hallway — get missed because they depend on someone noticing, and whoever notices ends up doing them.
Proposal: one visible weekly card, three columns: Task, Do-by, Backup. At a fixed time each Sunday, list at most five tasks that must happen in the next seven days. Give each task one owner and one backup, plus a channel that reaches the owner. If the owner hasn't acknowledged by that evening, the backup takes it. If neither can, postpone with a one-line reason and carry it forward. Add a single "float" line: anything unlisted but noticed (a spill, an overflowing bin) goes there and counts for whoever did it.
Benefit: deadlines stop depending on who happens to be home; one interruption doesn't silently cancel a task; the float line blocks the "wasn't on the card" excuse; and the fairness argument is settled by what's written down rather than by who complains first.
Drawback: writing the card is itself a recurring chore, and if owners repeatedly fail to acknowledge, the backup quietly does most of the work while appearing only to have volunteered.
Evaluation: run it for two weeks and tally three numbers per week — tasks done on time, tasks postponed, tasks contested (two people saying it wasn't theirs, or one nobody took). Compare against the week before starting, if prior notes or messages record it. Keep it if on-time completions rise and postponements stay flat; abandon it if postponements rise or the card ends up recording work nobody actually does.
This is a proposed trial, not a demonstrated result.