Little Lab Coats

Redesign Using Test Evidence

Engineering — Disaster-Resistant Design | Unit 1, Lesson 5 of 6

📚 Grade: 4th Grade⏱️ Duration: 45–60 minutes🛠️ Subject: Engineering — Disaster-Resistant Design

🔁📊🏠

Redesign works best when changes connect directly to evidence.

📋 NGSS Standard:
3-5-ETS1-1 / 3-5-ETS1-2 / 3-5-ETS1-3 — Define a design problem with criteria and constraints, generate and compare solutions, and plan fair tests with variables controlled and failure points considered.

🎯 Learning Objective

Students will redesign their storm shelter by choosing evidence-based improvements and explaining why those changes should help.

💡 The Big Idea

Redesign is stronger when it responds to real failure points instead of random new ideas.

🔬 Engineering Thinking

Science Snapshot

Evidence-based redesign focuses on the most important weakness first.

What is happening?

Redesign is strongest when it is driven by evidence from the first test. Engineers revise the feature that caused the failure rather than changing everything randomly.

Why it works that way

If wind tipped the shelter, the redesign may need a wider base or stronger bracing. If rain got inside, the roof angle or seams may need improvement. Good redesigns are targeted and explain why that change should help.

Look for this in the lesson

Students should use because-language tied to observations. That habit teaches that revision is part of scientific problem solving, not a sign the first idea was worthless.

Ask while you read: Which single design change is most likely to improve performance on the next test?

Materials

Printed lesson pages and worksheet
Version 1 notes
Pencil
Optional building materials for updated sketch

Let's Get Started

Step 1 — Review version 1 evidence
Identify the most important problem from the first test.

Step 2 — Choose targeted changes
Select one or two changes likely to improve performance.

Step 3 — Predict version 2 performance
Explain why the redesign should work better.

Step 4 — Sketch version 2
Label the new parts or changes.

Step 5 — Prepare to defend the redesign
Students connect each change to a specific piece of evidence.

Discussion Questions

Why should redesign connect to evidence?Evidence helps engineers make purposeful improvements.

What is a weak redesign?A change made for no clear reason.

How many changes should students make at once?Usually one or two clear changes so the evidence stays useful.

Why compare version 1 and version 2?Comparison shows whether the redesign improved performance.

Extensions

Extension: Ask someone at home whether your redesign directly solves the biggest problem from version 1.

Parent/Teacher Notes

Teaching note: Ask students to finish the sentence “I changed ___ because version 1 showed ___.”

Misconception to catch: Bigger or heavier is not always better if it creates new problems.

Student Worksheet

Name: ________________________ Date: ________________________

1️⃣ Evidence from version 1

Name the exact failure point first: leaking roof, tipping base, weak wall, or another observed problem.

2️⃣ My redesign change

Change	Which failure point or evidence led to it?	Why this should help in version 2

3️⃣ Sketch version 2

✂️ PARENT ANSWER KEY — Detach before giving worksheet to students

Sample ideas

If the roof leaked, a student might add a steeper angle or overlap layers because version 1 let water through the top seam. If the shelter tipped, a student might widen the base or strengthen supports because version 1 leaned or fell during the wind test.

✅ What Success Looks Like

Student names a specific failure point or piece of version 1 evidence first.
Student connects each redesign choice to that evidence instead of proposing a random change.
Student predicts how version 2 should improve the shelter under the same kind of test.