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IB Design Technology
SL · Lesson 19 · Human-Centred Design Challenge
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Lesson 19 · Unit 3

Human-Centred
Design Challenge

Synthesize research, ergonomics, inclusive design, product analysis and responsibility in one fast redesign sprint.

80 minutesA1.1 + B1.1 + C1.1/C1.2Integrated application
Guiding question: How do multiple human-centred design lenses combine to improve one product?01
Today’s destination

By the end of class, you should be able to…

01

Retrieve prior learning

Use UCD, ergonomics, percentiles, usability and product analysis without prompts.

02

Analyse a product

Identify evidence-based strengths, weaknesses and barriers.

03

Prioritize requirements

Make justified trade-offs for users and stakeholders.

04

Communicate a redesign

Present a concept with clear evidence links, not decoration.

Success check: explain the concept accurately, then use it to make a justified design decision.
Know it → use it → explain the evidence.02
Design sprint

Redesign a shared classroom charging station.

The station sits on a high counter. Cables tangle, status lights are small, some users cannot reach the back ports easily, and unplugging one device can disturb others. It must remain safe in a busy classroom and support multiple users.

UCDErgonomicsInclusive designUsabilityResponsibility
Your job is to connect evidence—not invent random features.03
10 minutes

Translate the brief into design evidence.

User

Who needs access?

Different reach, dexterity, vision and device needs.

Task

Connect → confirm → remove

Observe where errors and interference occur.

Environment

Busy shared classroom

Crowding, movement, liquids, cable hazards.

Stakeholders

Students + staff + school

Access, safety, durability and maintenance.

Use the U-T-E lens before sketching.04
10 minutes

Which human-factor requirements matter most?

LensQuestionPossible evidence
ReachCan intended users reach all ports?Low-percentile reach / layout test
ClearanceCan hands and devices move without collision?Hand/device dimensions + observation
VisionCan status be understood at a glance?Target size, contrast, redundant cues
Muscle control / dexterityAre connectors stable and easy to align?User attempts, error rate, insertion force
Pick evidence that can later become a specification.05
10 minutes

Analyse the current product before replacing it.

Preserve

What already works?

Capacity, charging performance, compact footprint?

Improve

What creates failure?

Reach, cable interference, unclear status, unstable connectors?

Test

What needs evidence?

Connection time, errors, accessibility, cable movement, safety.

Constructive discontent: specific + evidenced + actionable.06
10 minutes

Choose one extreme user to expose hidden barriers.

Limited reach

What if the back row is inaccessible?

Could layout or orientation bring all interaction forward?

Low vision

What if colour-only LEDs are insufficient?

Could shape, text or spatial mapping add redundancy?

Limited dexterity

What if alignment is difficult?

Could guides, larger targets or cable management reduce precision demand?

Extreme-user requirements may improve mainstream usability too.07
Apply it

Trade-off decision

A redesign places every port at the front for easier reach, but the exposed cable loop now creates a trip / snag hazard in a busy classroom.

What should the team do?

Choose before you reveal the feedback.08
Specification preview

Turn evidence into success criteria.

1
One human-factor requirement (reach / clearance / force / visibility).
2
One usability requirement (learnability / efficiency / errors / satisfaction / memorability).
3
One responsibility requirement (safety / durability / community / environmental impact).
Every requirement should be traceable to evidence or a justified design need.09
15 minutes

Communicate one redesign concept.

1
Sketch the main layout / form clearly.
2
Annotate 5–7 key features.
3
For each feature, name the requirement or evidence it responds to.
4
Identify one trade-off you still need to test.
Annotation should explain design reasoning, not label obvious parts.10
10 minutes

Critique the evidence chain, not the drawing style.

Ask

“What evidence supports this feature?”

Push beyond preference.

Test

“Who might still be excluded?”

Use inclusive design.

Challenge

“What new problem does this create?”

Use responsibility and trade-off thinking.

Professional critique makes reasoning stronger.11
Spiral retrieval

Which course concept answered each question?

QuestionConcept
Who struggles and why?UCD + user research
Can users reach / fit / manipulate it?Ergonomics + anthropometrics
Can more people access it?Inclusive design + design for extremes
How well does the current product perform?Product analysis + usability
What wider consequences exist?Responsibility of the designer
This is how IB topics connect in real design work.12
Knowledge check

Can you retrieve it without looking back?

1. Which concept helps decide whether a control is within usable reach?
Anthropometrics / ergonomics, using relevant percentile reach data.
2. Which concept helps challenge a colour-only status light?
Physiology/psychology and inclusive design, because colour perception and sensory variation matter.
3. Which tool turns observed user friction into a redesign opportunity?
Task analysis / user journey and product analysis.
4. Why should a redesign requirement be traceable to evidence?
Because specifications should communicate justified success criteria rather than preferences.
Say the answer first. Then reveal it.13
Exit ticket

Before you leave…

1. State one feature in your concept and the evidence it responds to.
2. Name one trade-off you identified.
3. Write one requirement that could be tested objectively.
Next lesson

Problem Statements & Design Specifications

Keep the evidence chain moving: user → research → decision → test.

Curriculum alignment
Integrated application of A1.1 ergonomics · B1.1 UCD · C1.1 responsibility · C1.2 inclusive design · C3.1 product analysis, preparing for B2.1 problem statement/specifications.
Lesson complete14 slides
Designed by David Xu · © 2026 David Xu. All rights reserved.Educators and students are welcome to use these materials for non-commercial teaching and learning with attribution. Please share the original link when possible. Reposting, redistributing modified copies, removing attribution, or commercial use requires prior permission.
IB Design Technology SL · Lesson 1914
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