A durable recording and feedback system.

Carroll (1977) built a reusable data sheet.

It is a thin plastic board. You write on it with a special pen.

Only paint remover wipes the ink away, so the day’s scores stay on the wall until you choose to erase them.

The sheet survives spills, smudges, and curious hands.

Staff can post daily feedback in shared areas without laminating or re-printing.

Rilling et al. (1969) came first. They taped a cheap time-lapse camera to the ceiling and filmed kids. The film gave a lasting picture, but you still had to watch hours of tape.

Poppen (1972) wired hand tools with transducers. Every time a worker used a tool, the machine counted it. The count matched finished products pretty well, but you needed wires and solder.

Halbur et al. (2024) updated the idea. They printed prompt boxes and random-order lists right on today’s paper sheets. Therapists followed the steps more closely, but the sheets still go in the trash after one use.

Carroll (1977) sits in the middle: more durable than paper, simpler than cameras or circuits, and greener than single-use sheets.

You can make the 1977 board in five minutes with a transparency sheet and a marker that says “permanent.” Post it at the child’s eye level. The score stays up all day, so staff, peers, and the learner see progress in real time. At night, one swipe of solvent clears the board for tomorrow. No paper waste, no lost data, no tech failures.