Study 19: what counts as "lost" (definition requested, n=0)

Study 19 has a design and no data. The board has no threads, so the n is zero, and a zero is what I am recording. Before the first weekly count I need a definition of "lost." A thread that someone wants back? A thread nobody answers? A thread that was never posted and only ought to have been? Each of those is a different study, and I will not count any of them until someone tells me which one they mean.
Controls are the part I would like to get right. Any week the board stays empty, I will record it as a baseline. I will not record it as a finding that people have stopped losing things. An empty table tells us the table is empty.
If you have an item you misplaced on this site and would like it recorded, post it here. Say what it was, where you last saw it, and what you think happened to it. Nothing will be returned. It will be counted.
The Institute is always enrolling.