Unit Plan 33 (Grade 8 Science): Engineering Communication Systems

Focus: Design, build, test, and improve a device that uses waves (sound, light, or other EM waves) to transmit information, using digitized signals where appropriate and applying an engineering design process to evaluate and refine solutions.

Grade Level: 8

Subject Area: Science (Physical Science – Waves & Information • Engineering Design)

Total Unit Duration: 5 sessions (one week), 50–60 minutes per session

I. Introduction

In this unit, students apply what they’ve learned about waves, analog vs. digital signals, and reliability to build a simple communication system. Working in teams, they design a device that uses sound, light, or another wave to send messages from a transmitter to a receiver (e.g., light flash code, buzzer code, string phone, or hybrid designs). Students must identify criteria and constraints, choose how to encode information (often using digitized patterns), and then test and improve their designs. By the end of the unit, they can use qualitative scientific and technical information to explain why their design choices (especially digital encoding) make communication more reliable.

Essential Questions

• How can waves (sound, light, radio, etc.) be used to transmit information from one place to another?
• What makes a communication system more or less reliable, especially when there is noise or interference?
• Why are digitized signals (like on/off or 0/1 patterns) often better than analog signals for accurate communication?
• How can we use an engineering design process—developing models, testing, and revising—to improve a communication device?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Describe how waves (sound or EM) can carry information using patterns (on/off, pulses, or other codes).
2. Integrate qualitative scientific and technical information about analog vs. digital and noise to justify using digitized signals in their communication design.
3. Define criteria and constraints for a communication system (e.g., distance, clarity, speed, materials) and propose at least two design ideas.
4. Develop and use a model or plan of a communication device, then construct, test, and modify the design based on data about reliability.
5. Collect and analyze test data (success rate, number of errors, time to send a message) to evaluate competing designs and choose the more reliable one.
6. Communicate a clear design argument explaining why their final device is effective and how digitized signals improve reliability.

Standards Alignment — 8th Grade (NGSS-based custom)

• MS-PS4-3 — Integrate qualitative scientific and technical information to support the claim that digitized signals are more reliable than analog signals for transmitting information.
• MS-ETS1-2 — Evaluate competing design solutions using a systematic process to determine how well they meet criteria and constraints.
• MS-ETS1-3 — Analyze data from tests to determine similarities and differences among several design solutions and to identify the best characteristics of each.
• MS-ETS1-4 — Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved.

Success Criteria — Student Language

• I can explain how my device uses waves to send a pattern that carries information.
• I can use information about analog vs. digital signals and noise to explain why digitized signals make my design more reliable.
• I can state the criteria and constraints for my communication system and show how my design meets them.
• I can test my device, record data (like success rate and errors), and compare different designs using that data.
• I can revise my design based on test results and explain why my final design is the best option we tried.