Communication with Light & Sound

For 6–7 year-olds, teach communication with light or sound as a design-build-test-improve engineering task: the child defines a real problem (send a message to a friend across a distance who can't hear them), plans and physically builds a device (cup-and-string telephone for sound, a torch signaller for light, or a drum for a beat pattern), agrees a shared CODE with the receiver so the device carries real information, then tests it over a measured distance and improves it. The big idea is that communication is information transfer — not merely making light or noise. The underlying physics (why light or sound carries the signal) is deferred to later years and need not be explained here.

• Thinking the device just needs to make light or sound, rather than carry an AGREED message over the distance — communication is information transfer, not mere output.
• Treating design as one-shot ('I built it, I'm done') instead of an iterative test-and-improve process.
• Believing a string telephone works best SLACK — in fact the string must be taut to carry the vibration; a loose string kills the signal.
• Assuming a louder or brighter device is automatically 'better', rather than testing whether the message actually gets across clearly at the far end.
• Confusing 'communicating' with just making a noise or shining a light at someone — with no shared code, no information is sent.

• The design–build–test–improve loop shown as an iterative cycle (define → plan → build → test → improve).
• Cup-and-string telephone (sound) and torch/flashlight signaller (light) as the two canonical build options.
• A simple agreed code/key (a flash pattern or drumbeat = an agreed message) — the information the device carries.
• A distance-measured test track — how far away can the message still be received clearly?

• Open with a defined, relatable problem ('send a message to a friend across the room / who can't hear you') per K-2-ETS1-1, so the build has a real purpose.
• Run the FULL iterative cycle — define → sketch/plan → build → test over a real distance → improve — and normalise redesign rather than expecting a one-shot product.
• Provide real tools and materials and let children physically make the device (cup-and-string telephone, torch signaller, drum); keep focus on whether the signal gets across, not on explaining the physics (assessment boundary).
• Have children sketch or model their design to communicate it before/while building (K-2-ETS1-2).
• Agree a simple shared CODE (one flash = yes; a drum pattern = a message) so the device carries real information — communication is information transfer, not just making light or noise.
• Test and compare: measure how far the message still carries, and weigh two devices' strengths and weaknesses (K-2-ETS1-3, integrating simple 1.MD measurement).
• Connect to real communication technologies (telephone, lighthouse, drums, semaphore) so children see that devices carry information over distance (DCI PS4.C).