Activity 01
Inquiry Circle: Design a Flash Code
Pairs agree on a simple binary code such as one flash for yes and two flashes for no. They write four questions for their partner to answer using only flashes, then test from across the room and record how many answers were received correctly before refining their code.
Design a system to send a message using only light.
Facilitation TipDuring Collaborative Investigation: Design a Flash Code, remind students to test their code with a partner before finalizing the flash pattern to ensure clarity.
What to look forObserve students as they test their light signaling devices. Ask: 'Can your partner understand your message? What part of your signal is confusing?' Note which students can identify a problem with their design.
AnalyzeEvaluateCreateSelf-ManagementSelf-Awareness
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Activity 02
Simulation Game: Semaphore School
The teacher demonstrates a simplified card semaphore system: red card up means letter A, blue card up means letter B. Small groups practice sending and receiving three-letter words across the classroom, then discuss what made some signals easier to read than others.
Evaluate the effectiveness of different light signals for communication.
Facilitation TipWhen running the Simulation: Semaphore School, model proper arm positions slowly so students can mimic the exact angles required for each letter.
What to look forAfter students have attempted to send a message, have them switch roles. The receiver should explain what they thought the sender's message was. The sender then states if the message was received correctly and suggests one change to make it clearer.
ApplyAnalyzeEvaluateCreateSocial AwarenessDecision-Making
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Activity 03
Gallery Walk: Light Signals in the Real World
Post images around the room showing real light signals: a traffic light, a lighthouse, brake lights, an emergency vehicle light bar, and a crosswalk signal. Students walk around and write on sticky notes what message each signal sends and which group of people it is designed for.
Compare how light signals are used in everyday life for safety and information.
Facilitation TipFor the Gallery Walk: Light Signals in the Real World, assign pairs to prepare a 60-second explanation of one artifact’s purpose and how it encodes information.
What to look forProvide students with a slip of paper. Ask them to draw one way light is used to send a message and write one sentence explaining how it works.
UnderstandApplyAnalyzeCreateRelationship SkillsSocial Awareness
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Activity 04
Formal Debate: Which Signal Fits the Situation?
Present two contrasting scenarios: sending a message across a foggy field and sending a message in a noisy stadium. Small groups argue which situation calls for a light signal versus a different type of signal, backing their choice with evidence from their investigation.
Design a system to send a message using only light.
Facilitation TipDuring the Structured Debate: Which Signal Fits the Situation?, provide sentence stems like 'This signal works because…' to keep arguments focused on evidence.
What to look forObserve students as they test their light signaling devices. Ask: 'Can your partner understand your message? What part of your signal is confusing?' Note which students can identify a problem with their design.
AnalyzeEvaluateCreateSelf-ManagementDecision-Making
Generate Complete Lesson→A few notes on teaching this unit
Teach this by starting with familiar examples students already use daily, such as remotes or traffic lights. Avoid over-explaining theory upfront; let the problem-solving reveal the need for structure. Research shows students grasp encoding better when they experience the frustration of unclear signals firsthand, so design tasks where failure is informative rather than discouraging.
Successful learning looks like students designing codes that others can interpret correctly on the first try. They should explain why their pattern works and adjust it when messages are misunderstood. By the end, they connect their device’s structure to the need for agreed-upon signals.
Watch Out for These Misconceptions
During Collaborative Investigation: Design a Flash Code, watch for students who assume any flashing light will work. Redirect them by asking, 'Will your partner understand if the light just turns on and off randomly? What makes the pattern meaningful?'
During Collaborative Investigation: Design a Flash Code, point out everyday examples like car turn signals or a TV remote using infrared light to show light communication happens at all scales, including short ranges.
During Collaborative Investigation: Design a Flash Code, watch for students who believe the light itself is the message. Have them compare random flashing to a coded sequence and ask which one their partner could actually interpret.
During Collaborative Investigation: Design a Flash Code, ask students to test whether a super-bright but non-patterned signal successfully delivers information to help them see that structure matters more than intensity.
During Collaborative Investigation: Design a Flash Code, observe if students design signals that are simply very intense. Hand them a dimmer switch or shaded flashlight and ask them to send a message without changing the pattern.
During Collaborative Investigation: Design a Flash Code, remind students that brightness alone does not improve communication, and guide them to focus on consistent patterns instead.
Methods used in this brief