What my three year old taught me about UX



I was driving with my three year old daughter one day. She asked me where we were going. I told her we were going to the swimming pool.

3yo: “Why?” Me: “Well I thought it would be nice to go swimming today” 3yo: “Why?” Me: “Because I thought it would be nice for you and Daddy to do something together” Her: “Why?” Me: “Because it gives Mummy some time to rest” Her: “Why?” Me: “Because she’s tired and needs some time on her own. (READ: Because if Mummy doesn’t get an hour of peace she is going to lose her sh*t)” Her: “Why?” Me: “Because she hasn’t had a good night’s sleep in over six months. And parenting is exhausting” Her: “Huh?” Me: “Nevermind. Oh look we’re here…”

Now, I was of course delighted to go swimming with my daughter. My point is that a three year old demonstrated one of the best ways to find the root cause of an action or problem. To keep asking Why.


The technique that my daughter trapped me in is called the 5 Whys and it was developed by Sakichi Toyoda, founder of Toyota Industries, in the 1930s. It became popular in the 1970s and was used as part of Toyota’s lean manufacturing methodology developed by Taiichi Ohno.


The example he used was:

Why did the robot stop? The circuit has overloaded, causing a fuse to blow.
Why is the circuit overloaded? There was insufficient lubrication on the bearings, so they locked up.
Why was there insufficient lubrication on the bearings? The oil pump on the robot is not circulating sufficient oil.
Why is the pump not circulating sufficient oil? The pump intake is clogged with metal shavings.
Why is the intake clogged with metal shavings? Because there is no filter on the pump.
The solution? Add a filter to the pump.

Asking why is especially important when creating user stories.


A user story describes something someone wants to do and why they want to do it, so that designers and engineers can build solutions. The format used is typically:

“As a…[actor], I want to…[action], so that I can…[goal]”


An example might be:

“As a customer, I want to buy some food, so that I have something to eat”

But ask, “Why does the user want to have something to eat?” and the story evolves…

“As a customer, I want to eat a sandwich, so that I am no longer hungry”

Eating isn’t the goal. Satisfying hunger is.

The Why is so important, because it helps all parties work out a solution to a problem in potentially abstract ways. I have frequently seen user stories written without the goal included. Usually this is because the author can’t work out the reason why a user is doing something. That leads to classic stories such as:

“As a user, I want to provide my email address, so that the system has my email address”

It is not the goal of the user to provide their email address. Why does the system need the email address? So that marketing can push communications back out to the user. It is the goal of the service provider to get the user’s email address. Therefore the story should be:

“As a marketing manager, I want users to provide their email addresses, so that we can inform them of new products and services”

Never underestimate the importance of asking Why, and make it the core of all of your user research. You will find you end up with some interesting discoveries! And if you can’t find a reason for a user wanting to do something then it’s likely a valueless feature.

Be three years old again and keep asking “But why?”, and never let anyone, not even an adult, respond with just, “Because.”



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