Writing a specification a maker can use
'Make it nice' cannot be tested. A specification turns a user's need into statements you can measure a finished product against.
Lesson overview
What you'll learn in this lesson
Develop specifications to inform the design of innovative, functional, appealing products that respond to needs in a variety of situations
Key learning points
- • Start with the user, not the object
- • Turning findings into criteria
- • Measurable or it does not count
- • Anthropometric and ergonomic data
This lesson at a glance
- 30 minutes
- 18 parts to scroll through
- 4 quick checks
- Marked quiz at the end
- Gentle pace: short sittings with pauses
Words to know
Scroll down — the lesson carries on below
Watch & discover
Part 1 of 18
Watch first
Writing a specification a maker can use
An English teaching video on this topic from KS3-5 Design & Technology. Watch it, then scroll down for the lesson.
In a nutshell
Develop specifications to inform the design of innovative, functional, appealing products that respond to needs in a variety of situations
What you already know
Part 2 of 18
Before we start
What you already know
You should already know how to identify a user and describe a design problem in your own words.
Key words
Part 3 of 18
Key words
Words you'll need today
- Design brief
- A short statement of the problem and who it is for.
- Specification
- Measurable requirements the product must meet.
- Criterion
- One testable requirement.
- Anthropometrics
- Body measurement data used to size products.
- Ergonomics
- Designing so a product fits how people actually use it.
Learning cycle
Part 4 of 18
Learning cycle 1 of 2
From user need to criteria
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 5 of 18
Learn
Start with the user, not the object
Interview or observe the person you are designing for. A desk tidy for a nurse on shift and one for a Year 8 bedroom share a name and almost nothing else. Record what the user does, where, and what currently annoys them.
Explore the idea
Part 6 of 18
Learn
Turning findings into criteria
Each finding becomes a requirement. 'She loses pens down the back of the desk' becomes 'must hold at least six pens upright and not tip when one is removed'. Group criteria under function, user, materials, safety, cost and sustainability.
Quick check
Part 7 of 18
Quick check
Which is a usable criterion?
Reset break
Part 8 of 18
Pause
That's sitting 1 of 2 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Quick check
Part 9 of 18
Quick check
Anthropometric data gives...
Learning cycle
Part 10 of 18
Learning cycle 2 of 2
Making criteria measurable
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 11 of 18
Learn
Measurable or it does not count
Add numbers and test methods. 'Lightweight' becomes 'under 400 g'. 'Strong' becomes 'supports a 2 kg load for one minute without deflection over 3 mm'. If you cannot describe the test, the criterion is an opinion.
Explore the idea
Part 12 of 18
Learn
Anthropometric and ergonomic data
Use percentile data rather than your own hand. Designing a grip to the 5th to 95th percentile covers most users; designing it to yours covers one. Ergonomics also covers reach, force needed and how obvious the product is to use without instructions.
Quick check
Part 13 of 18
Quick check
A design brief mainly states...
Quick check
Part 14 of 18
Quick check
Designing to the 5th–95th percentile means...
Common mix-ups
Part 15 of 18
Common mix-ups
Things people often get wrong
- A brief is not a specification: the brief states the problem, the specification states testable requirements.
- Adjectives like 'durable' are not criteria until they carry a test.
- Designing to the average user leaves out roughly half of them.
Challenge round
Part 16 of 18
Game · Sort it
Which of these are true?
Drag each card into the right column. Tap a card first if dragging is fiddly.
True
Not true
Mastery quiz
Part 17 of 18
Marked quiz
End of lesson quiz: Writing a specification a maker can use
6 questions, marked with the reasoning shown. No timer.
1. Specifications should be...
2. Ergonomics is about...
3. 'Supports 2 kg for one minute' is good because...
4. User research should happen...
5. Sustainability criteria might specify...
6. A criterion with no test is...
Lesson round-up
Part 18 of 18
Lesson round-up
Ready when you are
Quiz score
Not sat
Games
Not played
Points this lesson
0
Best run
0 in a row
Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?
Ask LunaDo the work
Your written work for this lesson
This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.
Why the first prototype broke
A team designed a phone stand from 3 mm plywood. The brief said it must hold a 200 g phone at 60° and survive being knocked. The first prototype looked right but snapped at the joint after two knocks.
The team tested again and found the grain of the plywood ran across the narrowest part of the joint, so the wood split along it. They widened the joint from 8 mm to 20 mm, turned the piece so the grain ran along the load, and added a small fillet at the corner to spread the force.
The second prototype survived twenty knocks. It used 15% more material and took four minutes longer to cut — a trade-off the team recorded in their evaluation.
Written for Good Learning Co.
Reading questions
- Name the fault in the first prototype and explain why it happened.
- List the three changes the team made and what each one does.
- Write an evaluation of the second prototype against the brief, including the trade-off.
Design sheet
DiagramSketch two ideas with measurements and notes, then photograph the sheet.
2 labelled sketches
Evaluation
WritingWrite how well your idea meets the brief and what you would change next time.
6–8 sentences
Saved as you type.
Part 1 of 18 · Watch & discover