You Are Using the ‘5 Whys’ Wrong. Here’s How to Improve.

  1. You should not ask “why” — for multiple psychological reasons.
  2. And you should have a much clearer roadmap for when to stop than just arriving at your 5th ‘why’.

I. What is it?

But is “why” really the best question? And will you get to the root cause by the 5th question? No and no. Let me tell you why…

II. What are the 2 flaws?

Flaw #1

  • First, the cultural burden. If you know anything about Japan, you know it is different. Very different. So don’t assume that asking “why” is an exception. There are as many as three, or up to six ways to ask “why” in Japanese. I am not sure which “why” Toyota used, but whichever it was, it came with very different connotations than any western “why”.
  • As for the personal burden: As we grow up, parents ask us “why” we did this or that. Later on, our managers ask the same question. And because of this, there is an inherent interrogatory, even blame-attributing nature to “why”. This instantly triggers a stress response, and sets off a defense mechanisms — and you don’t want that feeling in your interviewee.
  • And finally, the semantic burden: Designers are encouraged to use open questions in interviews, like “who”, “what”, “where”, “when”, “how’ and “why”. But these actually represent three different categories. “Who, What, Where and When” are ‘ingredients’ — they are factual and precise. “How” is procedural, systematic. And “why” is past-oriented, motivational, and tends to be more abstract and ambiguous. It is a category on its own.

Flaw #2

III/a. What to ask instead of “why”?

  • Ask “how come” — though just a minor tweak, it appeals to the other person’s insights in a non-threatening way.
  • Just say “Tell me more…” or “Tell me about that”. Beyond communicating curiosity, this also allows your interviewee to share their thought process and reasoning.
  • Really build on previous answers you received. E.g. if your interviewee says “I didn’t have time to exercise”, instead of asking “Why didn’t you have time?” you could ask “Were you occupied with something else?” This transforms your question from what could be perceived as an accusation to one of interest and assistance.
  • Begin with “what”. This makes the answers more concrete. E.g. “What were the reasons for you not having enough time?”.
  • Use any of the ‘ingredient’ type questions, such as “Who, What, Where and When”, to get more precise and factual responses.

III/b. When to stop?

  1. events — “what happened?”
  2. trends — “does this event fit into a trend or pattern?”
  3. systemic structures — “what causes these trends and events to emerge?”
  4. mental models — “what assumptions, believes and values give rise to the structures?”
  • Consciously categorise the answers you receive from your respondent into one of the 4 levels. This helps you know where you are.
  • Be stubborn and do not stop until you have answers at least at level 3, but ideally at level 4.
  • If answers take you one level up, instead of down, that may mean you need to be open to new avenues of enquiry, and fork your questions to unearth multiple underlying causes.
  • Deliberately ask questions that take the conversation deeper. To go to level 2, ask things like “How often does this happen?”. To go to level 3, ask “Do you always follow this process?”. To go to level 4, ask “Do you agree with this process?”.
  • Don’t be afraid for the conversation to turn abstract. As mentioned above, being factual is not always the goal. Level 4 (mental models) is where things become less factual. But they also become more valuable, as the leverage of making change increases the further down you go. Responses at this level may describe mental models of an individual… but also of an organisation.

IV. An example

  1. “Why did the robot stop?” — The circuit has overloaded, causing a fuse to blow.
  2. “Why is the circuit overloaded?” — There was insufficient lubrication on the bearings, so they locked up.
  3. “Why was there insufficient lubrication on the bearings?” — The oil pump on the robot is not circulating sufficient oil.
  4. “Why is the pump not circulating sufficient oil?” — The pump intake is clogged with metal shavings.
  5. “Why is the intake clogged with metal shavings?” — Because there is no filter on the pump.
  1. “How often do welding robots stop due to the problem of missing filters?” —More often than in the past. (level 2: patterns)
  2. Is there an automated process to monitor oil pump or filter health? — There is no automated process, we rely on random checks. (level 3: structures)
  3. Why do you believe the organisation omits automated monitoring? — The factory used to operate faultless, and I believe we grew complacent. (entering level 4: mental models)

In closing

  • do not use “why” — it makes people defensive.
  • have a map of events-trends-structures-mindsets to understand if your questioning is going in the direction, and if it is time to stop.



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