Universal Design
Design for the most constrained user to surface problems everyone quietly shares
- Difficulty
- Moderate
- Time to result
- ~months to results
- Steps
- 5
- Confidence
- 75%
Universal design emerged from the 1960s disability rights movement on the insight that if you design for the most constrained users, whether young, old, large, small, or disabled, you identify user problems that are just extreme versions of problems many more users have. That focus reveals where to concentrate design effort, and the resulting solution frequently turns out better for everyone. The counter-lesson comes from designing for the average: a pre-F-16 investigation found no such thing as the average pilot, since taking even three measurements left almost no one in the middle range, so a cockpit built for the average fit no one and caused accidents until adjustable cockpits solved it. Curb cuts built for wheelchairs help everyone; screen-reader menus forced the hierarchical structure that makes mobile web usable; body armor redesigned for women proved lighter and more mobile for most men too.
Origin
Extracted from David Epstein's account of universal design, which grew out of the disability rights movement of the 1960s, alongside the pre-F-16 average-pilot cockpit study.
Core principles
- 01The most constrained users experience extreme versions of problems many users have.
- 02Designing for extremes shows you where to focus your effort.
- 03There is no such thing as the average user to design for.
- 04Solutions built for a small constrained group often benefit the majority.
How to run it
- 1
Identify the most constrained users
Find the users at the extremes, those who are youngest, oldest, smallest, largest, or have disabilities, whose difficulties are most pronounced.
Watch out Do not design for the average user; on even three measurements almost no one is actually average.
- 2
Treat extremes as amplified common problems
Recognize that the constrained users' problems are usually extreme versions of frictions many typical users quietly experience.
- 3
Design to solve the extreme case
Build directly for those constrained users, using their needs as a sharp lens on where design effort matters most.
- 4
Validate the generalized benefit
Check whether the solution improves the experience for mainstream users, as curb cuts and hierarchical menus did.
- 5
Roll out and rebrand broadly
Extend the solution to everyone. The Army redesigned body armor for women, then had to rebrand it unisex because so many men wanted the lighter, more mobile version.
Pro tip If a constrained-user solution is quietly adopted by the majority, make it the default.
In the wild
When women first entered close combat roles, the Army found existing body armor far too heavy and designed lighter, more mobile, mix-and-match armor for them, with details like a notch for a hair bun. It turned out everyone wanted to raise their head while prone and shoulder a rifle, so the armor built for one to two percent of the force worked better for many men, and had to be rebranded unisex.
→ Gear designed for a tiny constrained group became better for a large share of the force.
After a spate of Air Force accidents first blamed on pilot error, a young lieutenant measured pilots and found that on even three measures like arm length, thigh circumference, and height, only about three percent fell in the middle range. A cockpit built for the average pilot fit no one; adjustable cockpits fixed it.
→ Abandoning the average and designing for variation sharply cut accidents.
Common mistakes
Designing for the average user
The average user does not exist; a design built around mean measurements fits almost no one and can be actively dangerous, as the average-pilot cockpit showed.
Treating accessibility as a niche cost
Viewing constrained-user design as a compliance expense misses that it is a compass pointing to improvements that benefit the whole user base.
Is it for you?
Best for
Product designers and engineers looking for a compass on where to focus design effort.
Not ideal for
Cases where the constrained users' needs genuinely conflict with the mainstream and cannot generalize.
From the transcript
“If you design for the most constrained users... you'll often be identifying user problems that are just extreme versions of problems that many more users…”
“In designing this cockpit for the average pilot, they had actually designed it for no one.”
From the episode
Why You Feel Overwhelmed All The Time (and how to fix it) - David Epstein - #1121
David Epstein