Testing Designs

Unit and Lesson Context

Unit: Building Bridges: Engineering Skills
Lesson: 5 of 8
Duration: 45 minutes
Year Level: 8
Class Size: 20 students
Subject: Technology (Design and Technologies)
Curriculum Reference: NSW Design and Technologies Syllabus (Years 7-8)

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Learning Objectives

By the end of this lesson, students will be able to:

1. Test prototype bridge models to measure stability and weight capacity through hands-on experiments.
2. Collect, record, and interpret data collaboratively to evaluate performance relative to design criteria.
3. Critically evaluate their own and peers’ designs, identifying strengths and areas for improvement.
4. Communicate findings using appropriate technical language and graphical means.

These objectives align with the NSW Technologies curriculum for Years 7 and 8, particularly:

• Design and Technologies Outcome:
  • "Create and adapt design ideas, processes and solutions, and justify decisions against developed criteria that include sustainability"
  • "Communicate design ideas and solutions using technical terms and graphical representation techniques"
  • "Independently and collaboratively document and manage production processes to safely produce designed solutions"
    (Source: Design and Technologies Achievement Standard - Years 7 and 8)

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Curriculum Linkages

NSW Technologies Curriculum - Design and Technologies (Years 7-8)

• Knowledge and Understanding:

  • Investigate how forces and load affect structural designs.
  • Understand the impact of materials and design features on the stability and strength of bridges.

• Processes and Production Skills:

  • Plan and conduct tests to evaluate designed solutions against criteria.
  • Collect and analyse data collaboratively to make judgments about design performance.
  • Use appropriate technical terms to discuss and document design findings.

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Lesson Breakdown

Time	Activity	Description
0–5 min	Introduction and Learning Intentions	Teacher outlines the focus: Testing and evaluating bridge prototypes. Recap prior lessons about designing and building bridges. Introduce the day's goals and safety considerations for testing.
5–25 min	Hands-On Testing Experiment	Students, in their groups (4-5 per group), test their prototype bridges by:

• Measuring stability: gently applying side forces and observing movement.
• Testing weight capacity: gradually adding known weights (e.g., sandbags or weights) until the bridge fails or bends beyond criteria.
• Recording quantitative data (max weight supported) and qualitative observations (e.g., flexing, cracking).
  Teacher circulates, scaffolding data collection and ensuring safety protocols. | | 25–35 min | Data Analysis and Group Discussion | Groups compile their test data on structured worksheets or digital sheets:
• Calculate average weight capacity if multiple tests done.
• Discuss how design features contributed to performance.
• Reflect on unexpected behaviours or failures.
  Teacher facilitates whole class sharing: groups present key results and discuss insights. | | 35–42 min | Evaluation and Improvement Planning | Using data and peer feedback, students evaluate how well their designs met criteria:
• Identify design strengths and areas for improvement.
• Propose modifications to improve bridge stability or load capacity.
  Teacher guides students to link evaluation to design decisions and sustainability considerations. | | 42–45 min | Reflection and Closure | Quick plenary: Teacher recaps the importance of testing and evaluating in engineering. Students note down one learning from today's testing and one idea to improve their design. Teacher outlines next lesson preview (refinement and redesign). |

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Resources Required

• Student-built bridge prototypes (from previous lessons)
• Standardised weights (sandbags, dumbbells, or similar)
• Data recording sheets or tablets/laptops
• Safety equipment (e.g., goggles if needed, safety rules poster)
• Whiteboard/chart paper for group presentations

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Assessment

Formative Assessment:

• Observation of student collaboration and testing procedures.
• Review of recorded data and evaluation worksheets.
• Quality of group presentations and ability to use technical language in explaining design performance.

Summative Link (Lesson 8):

• This lesson’s data and evaluation will provide critical evidence for students’ final design review in the unit.

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Differentiation and Support

• Provide scaffolded data sheets with prompts for students who need it.
• Allow use of digital tools for data recording and presentation for tech-savvy students.
• Support students with limited motor skills by assigning roles such as data recorder or timekeeper.
• Extend higher-ability students by encouraging them to hypothesise causes for failures using engineering principles (e.g., forces, tension, compression).

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Teacher Notes

• Emphasise the iterative nature of engineering: testing is not about "seeing if it breaks," but learning how to improve the design.
• Facilitate constructive peer feedback that is specific and linked to design criteria and safety.
• Remind students of safety measures around testing bridges with weights.
• Use questioning to deepen understanding, e.g., "Why do you think your bridge failed here?"; "How does this design feature affect load distribution?"

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Language and Terminology to Encourage

• Stability
• Load capacity
• Load distribution
• Force (compression, tension)
• Structural failure
• Prototype
• Criteria
• Evaluation
• Modification

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This lesson capitalises on collaborative experimentation and critical reflection in line with the NSW curriculum focus on practical engineering processes and thoughtful evaluation of designed solutions.

Would you like me to help generate the linked worksheets or student handouts to accompany this lesson?