Lesson 31 · Unit 4
Physical Modelling —
Aesthetic vs Functional
Build physical prototypes that answer the right question about scale, shape, space, appearance or performance.
80 minutesB2.2.2 + A2.2.4Physical models
Scale
Shape + space
Function
Guiding question: How should the purpose of a physical model influence its fidelity, materials and construction?01
Today’s destination
By the end of class, you should be able to…
01
Distinguish model purposes
Explain differences between aesthetic and functional physical prototypes.
02
Use fidelity strategically
Construct/interpret prototypes at different levels of fidelity.
03
Consider scale, shape, space
Use physical models to investigate these required B2.2.2 considerations.
04
Plan evidence
Choose what data/feedback a model should generate next.
Success check: explain the concept accurately, then use it to make a justified design decision.
Know it → use it → explain the evidence.02
B2.2.2
They are 3D tangible representations developed at different fidelities.
Scale
How big?
Overall dimensions, fit, reach and proportion.
Shape
What form?
Curvature, profile, grip, geometry and visual language.
Space
How does it occupy / interact with space?
Clearance, storage, surrounding objects and user movement.
B2.2.2 explicitly requires scale, shape and space.03
Physical model purpose
Aesthetic models emphasize appearance and form.
1
Overall proportion and silhouette.
2
Surface, colour, texture and perceived quality.
3
Visual relationship among components.
4
May have limited/no real function.
Aesthetic fidelity is useful when user judgement depends on appearance/form.04
Physical model purpose
Functional models emphasize operation and performance.
1
Mechanism / motion.
2
Load, stability or performance.
3
User operation and errors.
4
May look rough while function is realistic.
Functional fidelity is useful when performance is the uncertainty.05
Integrated fidelity
High-fidelity prototypes may combine both.
Model A
Beautiful shell, no mechanism
High aesthetic fidelity · low functional fidelity.
Model B
Working mechanism, rough foam body
High functional fidelity · low aesthetic fidelity.
Describe fidelity by the aspect being represented.06
Scale
Reduced/enlarged models can answer spatial questions without full-size cost.
1:1
Full scale
Best for direct human interaction and ergonomic checks.
1:2
Reduced scale
Useful for overall form, spatial arrangement and large products.
2:1
Enlarged
Useful for tiny details, mechanisms or interfaces.
Warning: some physical behaviours do not scale linearly, so interpret performance carefully.
Scale supports communication—but can limit realistic performance testing.07
B2.2.2
Simple models can reveal conflicts that drawings hide.
Shape
Grip, curve, edge, profile
Can a user hold it? Does the form communicate orientation? Do parts interfere?
Space
Reach, clearance, storage, movement
Does it fit the environment? Can users access controls? Is there room for assembly/motion?
Physical models make three-dimensional constraints visible.08
Apply it
Choose the model
A designer needs to evaluate whether users with different hand sizes can comfortably reach and operate a trigger while gripping a handle. Surface colour is irrelevant at this stage.
What prototype is most appropriate?
Choose before you reveal the feedback.09
B2.2.6 preview
A physical prototype should generate relevant evidence.
| Model purpose | Possible data | Possible feedback |
|---|---|---|
| Scale / reach | Reach distance, contact success | “Back control is hard to reach.” |
| Function | Cycles, load, time, errors | “Mechanism feels unstable.” |
| Aesthetic | Preference ranking | “Form looks too bulky.” |
| Space | Clearance / interference | “Cable collides with the hinge.” |
Next step: use feedback to develop the design iteratively.10
25 minutes
One concept, two different models.
A
Build a quick aesthetic model focusing on proportion / shape.
B
Build a quick functional subsystem focusing on one interaction or mechanism.
1
Write one question each model can answer.
2
Write one question each model cannot answer reliably.
Purpose determines what the model is allowed to claim.11
Vocabulary lab
Physical modelling vocabulary
Retrieve first. Then check.
TermPhysical prototypeClick to reveal
MeaningA 3D tangible representation of a design or system used to explore/test ideas.
TermAesthetic prototypeClick to reveal
MeaningA model emphasizing appearance, form, proportion, colour/texture or perceived quality.
TermFunctional prototypeClick to reveal
MeaningA model emphasizing operation, mechanism, interaction or performance.
TermScale modelClick to reveal
MeaningA representation at a defined proportional relationship to the intended product.
TermShapeClick to reveal
MeaningThe geometric/form characteristics of the product or component.
TermSpaceClick to reveal
MeaningHow the product occupies, fits within or interacts with surrounding three-dimensional space.
TermFidelityClick to reveal
MeaningHow closely the model represents relevant aspects of the intended product.
TermPerformance dataClick to reveal
MeaningMeasured evidence generated by testing how the prototype behaves or is used.
Say the meaning before you flip the card.12
Knowledge check
Can you retrieve it without looking back?
1. What three considerations are explicitly named in B2.2.2?
Scale, shape and space.
2. What is an aesthetic prototype mainly used to test?
Appearance/form-related aspects such as proportion, surface, colour, texture and visual relationships.
3. What is a functional prototype mainly used to test?
Mechanism, operation, interaction and/or performance.
4. Why might a 1:10 model be poor for a grip test?
Human interaction and ergonomic dimensions are not represented at full scale.
5. Can a prototype be high-fidelity functionally but low-fidelity aesthetically?
Yes. Fidelity can differ by aspect.
Say the answer first. Then reveal it.13
Exit ticket
Before you leave…
1. Identify one IA idea that needs a physical model.
2. State whether it should emphasize aesthetic or functional fidelity first.
3. Name the scale / shape / space question the model should answer.
Next lesson
IA Day 9 — Annotated Concept Development
Keep the evidence chain moving: user → research → decision → test.
Curriculum alignment
B2.2.2 construct/interpret aesthetic and functional prototypes at different fidelity levels, considering scale, shape and space · reinforcement of A2.2.4.
B2.2.2 construct/interpret aesthetic and functional prototypes at different fidelity levels, considering scale, shape and space · reinforcement of A2.2.4.
Lesson complete14 slides
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