Improving and Redesigning

Active learning works for improving and redesigning because students must physically test and change their designs to see real results. Hands-on iteration makes the cause-and-effect of changes visible and memorable, turning abstract feedback into concrete next steps.

• 2nd Grade
• Science
• 3 activities
• 15 min–35 min

Learning Objectives

1. Analyze test data to identify specific areas where a prototype failed to meet design criteria.
2. Modify a prototype based on evidence from testing to improve its functionality.
3. Justify design changes made to a prototype by explaining how they address specific test results.
4. Compare the performance of an original prototype with a redesigned prototype using quantitative or qualitative data.
5. Evaluate the effectiveness of iterative design in creating a more successful solution to an engineering problem.

Project-Based Learning

⏱ 15 min·Individual

Redesign Planning: Change One Thing

Before rebuilding, each student writes on an index card: (1) the specific problem they are fixing, (2) the change they plan to make, and (3) a prediction of what will be different in the next test. Groups discuss their cards with the teacher before beginning reconstruction. This structured pause prevents random changes and connects rebuilding to evidence-based reasoning.

Prepare & details

Design modifications to a prototype based on test data.

Facilitation Tip: During Redesign Planning, hand out sticky notes so students can record their single change before altering their prototype, preventing rushed multi-change attempts.

Setup: Flexible workspace with access to materials and technology

Materials: Project brief with driving question, Planning template and timeline, Rubric with milestones, Presentation materials

• Apply
• Analyze
• Evaluate
• Create
• Self-Management
• Relationship Skills
• Decision-Making

Project-Based Learning

⏱ 35 min·Small Groups

Build and Retest: Version 2

Groups implement their planned change and rebuild their prototype. Once complete, they run the same test using the same procedure as the first trial and record results in a side-by-side comparison table (Version 1 results vs. Version 2 results). Groups circle the values that changed and note whether each change was an improvement.

Prepare & details

Justify the changes made to a design to enhance its function.

Facilitation Tip: During Build and Retest, circulate with a clipboard to note which students are testing only their one change, redirecting any who are altering multiple variables.

Setup: Flexible workspace with access to materials and technology

Materials: Project brief with driving question, Planning template and timeline, Rubric with milestones, Presentation materials

• Apply
• Analyze
• Evaluate
• Create
• Self-Management
• Relationship Skills
• Decision-Making

Think-Pair-Share

⏱ 20 min·Pairs

Think-Pair-Share: Did It Work? Why?

After retesting, pairs discuss: did your change improve the design? How do you know? Each pair prepares one evidence-based claim to share with the class. During the whole-class share, the teacher charts improvements and unchanged areas to visualize which types of changes were most effective across all groups.

Prepare & details

Evaluate how iterative design leads to better solutions.

Facilitation Tip: During Think-Pair-Share, provide sentence stems like ‘The test showed the problem was ______, so I changed ______ to ______.’ to keep discussions focused on evidence.

Setup: Standard classroom seating; students turn to a neighbor

Materials: Discussion prompt (projected or printed), Optional: recording sheet for pairs

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

Teaching This Topic

Teachers should model frustration tolerance by narrating their own redesign process aloud: ‘This didn’t work the first time, so I’ll change only one thing and test again.’ Avoid rushing to perfection by giving students time to observe failures. Research shows that young engineers learn best when they explicitly connect test data to single-variable changes, building a habit of disciplined iteration.

What to Expect

Successful learning looks like students confidently using test evidence to name one design change, implementing it clearly, and explaining how the change addresses the original problem. You will see students take ownership of their process, not just their product.

Watch Out for These Misconceptions

Common Misconception

During Redesign Planning, watch for students listing multiple changes to make. They may say, ‘I’ll add more tape and make it shorter.’

What to Teach Instead

Hand them a sticky note and say, ‘Pick ONE change to test. Write it here before you touch your prototype. If you change two things at once, we won’t know which one helped.’

Common Misconception

During Build and Retest, watch for students declaring their design finished after any improvement, even minor ones.

What to Teach Instead

Ask, ‘Can you make it hold 2 more pennies? Try one small change and test again.’ Use the stretch goal to normalize continuous improvement.

Assessment Ideas

Quick Check

After Redesign Planning, collect sticky notes and check that each student’s change is specific and addresses the test evidence they collected.

Discussion Prompt

During Think-Pair-Share, listen for partners to name the original problem and explain how the new design fixes it using test results.

Peer Assessment

After Build and Retest, have students use a simple checklist to assess each other: ‘Partner named the problem, partner explained how the redesign fixes it, partner used test results to justify the change.’

Extensions & Scaffolding

• Challenge: Ask students to predict how many more pennies their redesign will hold before retesting, then compare predictions to results.
• Scaffolding: Provide a visual checklist with images of possible single changes (e.g., add supports, widen base, shorten span).
• Deeper exploration: Introduce a ‘constraint card’ with a new rule like ‘Use only 5 straws’ for Version 3, pushing students to optimize within limits.

Key Vocabulary

Prototype	An early model or sample of a product built to test a design or process. It is not the final version.
Iteration	The process of repeating a process or action, especially to improve a design or solution. It involves making changes and testing again.
Test Data	Information collected during testing that shows how well a prototype works or where it has problems.
Improvement	A change made to a design or prototype that makes it work better or solve the problem more effectively.