Tell me about a time you used data to change someone's mind. What was the analysis and how did you present it?

What the interviewer is looking for

• This question tests quantitative analysis & modelling. Explains models, assumptions and sanity checks clearly and draws sound business conclusions from data.
• What to bring out: Describes the question, the data and method, checks on accuracy, a clear presentation and the outcome.
• Expect a follow-up like: What was the weakest part of your analysis?

Another way it may be asked: Think of a time numbers helped you convince someone. What did you look at and how did you show it?

A structure to follow: STAR, with the weight on Action and Result

1. Step 1

   Situation

   One or two sentences: where, when and what was at stake. Pick a real example you were close to.

2. Step 2

   Task

   What you personally were responsible for. Say "I", not only "we", so the quantitative analysis & modelling you showed is visible.

3. Step 3

   Action

   The two or three things you did and why you chose them over the alternatives. This should be about half your answer.

4. Step 4

   Result

   What changed, in your own measure of it, and what you would do differently. Only use numbers you can stand behind.

This is guidance on shape, not a script. Use your own real experience and facts; never invent details to fill a gap. See the STAR guide and answer frameworks.

Common slips

• Describing what the team did without saying what you did.
• Choosing an example with no clear outcome, or one you cannot answer detailed questions about.
• Ending on the action and skipping the result and what you learned.

How to practise it

Write two bullet points for each STAR letter, then say the answer aloud in about two minutes.

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