Tell me about your greatest achievement

• Your standards. What you call your greatest achievement reveals where you set the bar. A result reached without particular difficulty says nothing, while a goal that looked out of reach says a lot.
• Your own contribution. The interviewer is hunting for the "I" behind the "we": what you decided, did and fixed, personally.
• Your tenacity. The passages where it nearly failed are the ones they listen to most closely.
• How you talk about it. You can tell an achievement with pride without showing off, and that balance is observed.

1. 1

   Pick an achievement that cost you something

   Ask yourself what you are proud of because it was not a given, rather than what looks impressive on paper. A modest success won against real obstacles beats a prestigious line that came easily.
2. 2

   Give the stakes and the starting point

   In two sentences: what had to be reached, and why it looked hard. Without that starting point the result has no depth.
3. 3

   Tell the obstacles and your actions

   This is the core. Two or three moments when you had to find a solution, change method or hold on when it was discouraging. Stay precise about what you did.
4. 4

   Give the result and what it taught you

   An observable result, with a number if a real one exists, then one sentence on what the experience showed you about how you operate.

"What I am proudest of is getting my school's tutoring programme for local secondary pupils back on its feet. When I took it over in my second year, there were four tutors and about ten pupils left, and the administration was talking about closing it. I gave myself a year to make it run without me.

The first obstacle was recruiting tutors. My announcements got nowhere, so I went to see those who had quit to understand why. They all said the same thing: they never knew whether their pupil would turn up. So I started by fixing that problem, calling each family myself the day before sessions for two months..."

This example is made up: it shows the tone and the construction, not a script to memorise. Your answer has to come from your own experience or from the data the interviewer gives you.

• Naming a degree or an exam without telling anything. Getting into a school is already on your CV, and put that way it reveals nothing more.
• Choosing a collective success where your role stays blurry. If the team won, say exactly what would not have happened without you.
• Erasing the difficulties to look brilliant. An achievement with no obstacle looks like luck.
• Inflating the numbers or the scope. Follow-ups go into detail, and an approximation that collapses costs you all your credibility.