Coded Requests at the Winter Sled Desk

Requests Through the Storage Window

In the snowy town of Alderford, families borrow equipment from a sled-lending building. A worker at the front desk sends requests to a helper in the storage room. A closed window separates the rooms. The workers can see through it, but speech is hard to understand. Fourth graders compare two devices for sending four supply requests.

The first device is a number card. It displays two large numbers side by side, with a dividing line between them. The storage helper reads the card from left to right. The sender holds the card facing the window for nine seconds, then lowers it. Each complete card request takes nine seconds.

The second device is a small battery-powered buzzer that plays two groups of beeps. Each group contains one or two beeps. A short pause separates the groups. A longer quiet pause marks the end of the request. The device takes six seconds to play a complete request, including the ending pause.

Both workers use the shared key below. A number on a card tells how many beeps belong in that position. For example, 1 | 2 matches one beep, a short pause, and then two beeps. The dividing line in the printed key marks the group break; it is not an extra beep.

The class tests both devices with the boot dryers off, when the storage room is quiet. An adult then turns the dryers on for another set of trials. In each condition, each device sends the same list of twelve requests. The workers, window, distance, code keys, and timing stay the same. Students count complete requests understood correctly. Their sample results appear in the graph.