Patterns & Codes for Information

Pupils aged 9–10 learn that information can be carried as patterns, and that coding is an engineering design task: invent a code, transmit a message as a light or sound pattern, have a partner decode it, and compare competing codes against explicit criteria (speed, distance, reliability in noise, ease of learning). The central experience is encode-THEN-decode with a partner using a shared key, so that 'communication needs an agreed code' is felt rather than told. A concrete→abstract progression (Morse → black/white pixel grids → everyday signals) builds toward the big abstraction that, when combined into longer patterns, any two distinguishable states can represent any message (letters, numbers or pictures), and toward the engineering habit of comparing multiple solutions rather than hunting for one 'right' answer.

• Confusing the MESSAGE with the CODE — not seeing that the same message can be sent by many different codes, and the code is a shared SYSTEM of patterns, not the message itself.
• Thinking any noise or flash 'communicates' — missing that communication needs an AGREED code both sender and receiver know (carried from the build-a-device prerequisite); an unshared key means no message gets through.
• 'More complex or longer codes are better' — not grasping efficiency/trade-offs (good codes give frequent symbols short patterns; the best solution depends on the criteria, e.g. speed vs noise-resistance).
• Treating binary as mysterious 'computer magic' — rather than simply two distinguishable states used as a pattern; any two different things work.
• Not seeing that pictures, numbers and text can ALL be reduced to patterns of two symbols — the core abstraction of digital representation.
• Assuming there is one 'right' code — rather than multiple candidate solutions to be compared against criteria and constraints (the engineering-design point of the standard).

• Morse dot/dash chart plus a tap/flash sender — patterns laid out in TIME (short vs long).
• Binary pixel-grid (e.g. a 5×6 letter 'C'; 0/1 = black/white) with an encode/decode worksheet where an image emerges as squares are filled.
• A 'two states' abstraction card — on/off, light/dark, thumbs up/down, two symbols — showing any two distinguishable things can carry information.
• A compare-solutions table: rows = codes (Morse, semaphore, drum, binary), columns = criteria (speed, distance, noise-resistance, learnability) — the engineering-evaluation organiser.
• A sender → coded pattern over light/sound → receiver diagram with a shared KEY, showing decode success (matched key) vs garble (missing/wrong key).

• Teach it as ENGINEERING design-and-compare, not decoding worksheets: pupils GENERATE their own code and COMPARE competing systems (Morse, semaphore, drum, binary) against explicit criteria — speed, distance, resistance to noise, ease of learning — which is the standard's actual demand.
• Run a concrete→abstract progression: Morse (tap/flash dots & dashes) → binary pixel-grid → everyday signals (traffic lights, thumbs up/down), ending in student-generated solutions rather than isolated decoding.
• Make encode-THEN-decode with a partner central (CS Unplugged): the message only arrives if both share the code, so a successful decode proves the shared system and a garbled one diagnoses a broken/unshared key — the 'agreed code' idea made experiential.
• Use the CS Unplugged pixel-grid ('Colour by Numbers'): a picture is a grid of black/white pixels = 0/1; pupils decode a digit-grid into an emerging image, then draw their own, write its binary and have a peer rebuild it — showing pictures are patterns too; note more colours need more digits per pixel.
• Exploit the efficiency principle as a built-in 'compare solutions' criterion: Morse gives frequent letters the shortest codes (E = one dot), so pupils can rank codes on how quickly they send typical messages.
• Establish the big abstraction explicitly — ANY two distinguishable states (on/off, light/dark, high/low, two symbols) can represent anything — so binary stops being 'computer magic' and becomes just the simplest possible pattern system.
• Connect to real systems and their history (telegraph, semaphore, drum signals, computer pixels) so 'patterns transfer information' is seen as a general, everywhere phenomenon, and pupils can compare old and new solutions.