Wool vs Cotton Investigation

Overview

In this third lesson of Exploring Food and Fibre, students compare wool and cotton through guided, low-risk investigations. They use evidence about warmth, softness and durability to decide which fibre is suitable for different products, then sequence how each fibre becomes yarn and fabric.

Learning intentions

Students will:

• describe observable properties of wool and cotton fibres
• conduct simple, fair tests and record evidence
• explain how a fibre’s properties influence product suitability
• sequence the production of wool and cotton from source to fabric

Success criteria

• I can describe at least three properties of wool and cotton.
• I can record observations and use evidence to compare the fibres.
• I can explain why one fibre is more suitable for a particular product.
• I can correctly sequence both fibre supply chains.

Curriculum links

• Explain how and why food and fibre are produced in managed environments.
• Explain how characteristics and properties of materials, tools and equipment affect their use.
• Investigate materials, components, tools, equipment and processes needed to create designed solutions.
• Select and use suitable materials, tools, equipment and techniques safely.

Lesson structure (60 minutes)

1. 0–5 min · Engage and retrieve. Display the opening comparison from the wool and cotton investigation deck and ask, “Would you choose wool or cotton for a winter jumper? What makes you think so?” Students silently choose, then share one reason with a partner. Briefly revisit that fibres are materials obtained from plants or animals and can be processed into products.

2. 5–13 min · Explicit teaching and modelling. Use the fibre properties teaching slides to introduce warmth, softness, durability, absorbency and suitability. Explain that a property is a characteristic we can observe or test, while suitability means how well a material meets a product’s purpose. Model a fair comparison: change only the fibre, keep the test method the same, observe carefully and record evidence. Demonstrate how to complete one row of the wool and cotton comparison organiser using a sentence such as, “Wool felt warmer because…”.

3. 13–30 min · Guided fibre investigations. Organise 32 students into eight groups of four. Assign roles: equipment manager, tester, recorder and reporter. Provide each group with labelled wool and cotton samples or fabric squares, a comparison organiser and the teacher-approved testing equipment. Students complete three guided tests:

• Warmth: place each sample over an identical container of warm water or around an identical warm object for a fixed time, then compare the temperature by carefully touching the outside or using thermometers if available.
• Softness: handle equal-sized samples and rate each using a 1–5 scale, explaining the rating.
• Durability: gently pull each sample with the same number of controlled tugs or attach equal small weights one at a time, observing stretching, fraying or change.

Students record results, not just opinions, and use “I observed…” statements. Reinforce safe handling, no tasting, gentle testing and respectful group cooperation. Circulate to ask, “What stayed the same in your test?” and “What evidence supports your rating?”

4. 30–40 min · Interpret and apply evidence. Students complete the property-to-product task on the product suitability section. They match each fibre to products such as a winter jumper, summer T-shirt, blanket, towel or sturdy bag, then justify two choices using a property and evidence from their tests. Pause halfway for a whole-class check: groups hold up a wool or cotton sample and explain one suitable use. Clarify that suitability can depend on more than one property and that testing conditions may affect results.

5. 40–52 min · Supply chain sequencing. Display the two supply-chain pathways in the supply chain sequencing slides. Give each group the pre-filled step cards in the worksheet resource: wool—sheep → shearing → cleaning/scouring → carding/spinning into yarn → weaving or knitting into fabric; cotton—cotton plant → harvesting cotton bolls → separating and cleaning fibres → spinning into yarn → weaving or knitting into fabric. Groups first predict the order, then arrange and check the cards. Students copy or draw both sequences in the organiser and identify the source of each fibre. Emphasise that managed production involves planned processes, tools and equipment that transform raw materials into products.

6. 52–60 min · Share and assess. Use the comparison discussion and exit slides to reveal a final product challenge: “Choose wool or cotton for a school hat, and defend your decision.” Invite three groups to share evidence-based answers. Students complete the final section of the individual reflection and exit response: one similarity, one difference, one suitable product and one correctly ordered supply-chain sequence. Collect worksheets as students leave.

Resources

• the wool and cotton investigation deck
• the wool and cotton comparison organiser
• Clean, labelled wool and cotton fabric or fibre samples
• Identical containers or warm objects and thermometers, if available
• Small weights, pegs or elastic bands for durability testing
• Trays, rulers and pencils
• Group role cards or displayed group roles
• Timer and board markers

Assessment

• Listen to partner explanations and question students about fair testing, controlled variables and evidence.
• Check comparison organisers for accurate property descriptions, recorded observations and justified product choices.
• Use the individual exit response to assess fibre properties, suitability reasoning and supply-chain sequencing.

Differentiation

• Provide a word bank with visuals: warm, cool, soft, rough, strong, weak, stretchy, absorbent, yarn, fabric.
• Offer sentence starters: “The wool was more suitable for ___ because ___” and “The evidence I recorded was ___.”
• Pair students strategically and allocate roles; allow students to demonstrate an answer orally before writing.
• Extend confident students by asking them to identify a limitation in one test and propose a more controlled investigation. Support EAL/D and students requiring adjustments with enlarged samples, repeated modelling, reduced writing load and teacher-scribed observations.