It’s one of the most powerful tools a designer has yet, just asking why isn’t enough but asking “Why?” My science teacher from High-School taught me this technique and over the years it's come in handy.

Sakichi Toyoda

The Five Why’s is an iterative questioning technique use to explore the cause-and-effect relationships underlying a particular problem.

Formally the technique was first developed by Sakichi Toyoda and played an important part in the evolution of Toyota’s manufacturing methodologies.


What makes this method so special is the simplicity and childlike nature.Pulling this out of the toolbox during interviews. Asking horizontal questions will not prove helpful — it’s all about going deep.

It’s simple, starting with a broad question, ask the person being interview “why?” after every answer but only doing so five times. At the end, things will come into focus.

The Materials Needed

+ Post-It Notes
+ Markers / Pens
+ Whiteboard / Blank Wall

How to Do It

Step 1:
Start by asking the other party a broad question.

Step 2: 
Ask the team to individually write down why that is happening.

Step 3: 
Form a new problem from the answers the team gave.

Step 4: 
Repeat steps 2 and 3 four more times or as much as necessary.

Final Step: 
Analyze the results and form relationships between answers.