Unit Plan 16 (Grade 4 Science): Designing Signal Devices

Focus: Build and refine simple devices that transfer coded information using light, sound, or motion, comparing how well different designs meet criteria and constraints.

Grade Level: 4

Subject Area: Science (Physical Science • Engineering Design)

Total Unit Duration: 5 sessions (one week), 45–60 minutes per session

I. Introduction

Students take what they know about waves and information transfer and apply it to engineering design. They are given a clear design challenge: create a signal device that can send a short coded message across the classroom using patterns of light, sound, or motion. Over the week, they generate multiple solutions, build prototypes, run fair tests (controlling variables like distance and noise), and use data to improve their designs. By the end, students can explain how their device works, how well it met the criteria, and why they chose one solution over another.

Essential Questions

• How can we use patterns to send information with light, sound, or motion?
• What makes one signal device more effective or reliable than another?
• How do criteria, constraints, and fair tests help engineers improve their designs?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Describe a design problem that involves sending coded information across a distance using a signal device.
2. Generate and compare at least two design ideas that use patterns (light, sound, or motion) to transfer information.
3. Build a simple prototype signal device that follows given criteria and constraints (distance, safety, clarity, materials).
4. Plan and carry out fair tests, controlling key variables (distance, message length, noise) and recording data on accuracy and reliability.
5. Use test data to suggest and implement improvements to the device, then explain why their final design is effective.

Standards Alignment — Grade 4 (NGSS-Aligned)

• 4-PS4-3 — Generate and compare multiple solutions that use patterns to transfer information.
  • Example: Build and test two different light-based signal devices that use flash patterns to send messages.
• 3-5-ETS1-2 — Generate and compare multiple solutions based on criteria and constraints.
  • Example: Compare a sound device vs. a light device using the same criteria (distance, clarity, ease of use).
• 3-5-ETS1-3 — Plan and carry out fair tests with controlled variables to identify improvements to designs.
  • Example: Test devices at the same distance and noise level, then change one part and retest.

Success Criteria — Student-Friendly Language

• I can explain the design problem and the criteria and constraints for our signal device.
• I can draw or describe at least two different device ideas that use patterns to send messages.
• I can build and test a device that sends a short coded message across the classroom.
• I can plan a fair test by keeping some things the same and changing only one part at a time.
• I can use data from our tests to improve our design and explain why our final device works well.